Introduction

We grew up during the Cold War (the long standoff between the US and USSR superpowers and their respective alliances) under the constant background threat of nuclear war. We didn't necessarily understand it very well - even the military, academic, and scientific communities did not - but it was a constant presence in our lives. Since the collapse of the Soviet Union, that's not been the case. Few people younger than their mid-30s know very much at all about nuclear weapons, strategy, or war - or what it all means in terms of our survival and our future. We'll try to narrow that gap of understanding, because the danger looms large again.

Nuclear history and why it matters

First, let's de-mythologize the topic. Nuclear explosives were made possible by inevitable progress in the science of physics in the early 20th century, progress that was not initially aimed at the production of weapons. The potential energy release from the process of nuclear fission was apparent, and since parallel research was underway in many countries including Nazi Germany in the 1930s, the implications could not be ignored. Abstinence was not an option.

The appeal of nuclear explosives was simple, although the science and engineering necessary to make them practical was not. That appeal lay in the ability to generate great destructive power with a device many orders of magnitude smaller in size and weight than the conventional explosives needed to produce a comparable effect. By mid-century, in World War 2, there was nothing novel about the application of great destructive power in war; it was a matter of industrial capacity, resources, and the human and technological ability to deliver such power to a chosen target. These included, for instance, the ability to design, test, produce, and deploy aircraft in sufficient numbers, that could fight their way through defenses across hundreds or thousands of miles carrying bomb loads of several tons each; effective bombsights allowing acceptable accuracy in high altitude bombing under varying conditions; and of course, well-trained and educated planners, commanders, crews, and ground support personnel.

America and Britain in particular excelled at all this, and to enemy populations in Germany and Japan in 1944-45, dying under explosive or incendiary bombardment from a mass bombing raid by hundreds or thousands of Allied bombers was qualitatively no different than dying under the single nuclear bomb exploded over Hiroshima. As Napoleon Bonaparte said two centuries ago, "Amateurs discuss tactics. Professionals discuss logistics." Nuclear weapons, after the sunk costs of the initial scientific and engineering development, were logistical miracles and Hiroshima is an illustrative example. One 15-kiloton nuclear bomb carried by a single bomber caused 70,000 immediate deaths (27% of the population), and as many or more from injuries by the end of the year; and leveled several square miles of the city. Such effects were not new or exceptional - Tokyo had recently suffered more deaths and greater destruction from repeated American firebombing by fleets of heavy bombers. But to do it so cheaply was a revolutionary advance in the grim science of war.

Aside from the logistical advantages of nuclear explosives, there was a new effect: nuclear radiation. We'll discuss this more in the detailed discussion of effects that follows.

The advantages of possessing nuclear weapons from a military and strategic viewpoint were almost universally accepted in the post-WW2 era - sometimes unrealistically so, because wholesale destruction is not the only, nor the most desirable purpose or effect of war. However, the race to master the technology and join the United States as a nuclear power led, by 1968, to a nuclear "club" of five great powers: the U.S., the Soviet Union, the United Kingdom, France, and China. These five were the initial signatories of the Nuclear Nonproliferation Treaty (NPT) of 1970, which still attempts to limit the spread of nuclear weapons to other nations. It has been somewhat successful, but not wholly so. Since the NPT's inception, nuclear weapons have been developed and deployed by several other nations: Israel (which still maintains an "ambiguous" stance, not openly acknowledging its capability), India, Pakistan, and North Korea.

Only a few nations have ever possessed nuclear weapons and given them up: South Africa, which voluntarily dismantled theirs in the 1990s; and Ukraine, Kazakhstan, and Belarus, three successor states to the U.S.S.R. that inherited weapons from the Soviet stockpile but transferred them to Russia and signed the NPT. Others had active nuclear weapons programs but abandoned them under diplomatic and/or military pressure, such as Libya and Iraq.

In addition, there are several "threshold" nations widely considered to be capable of producing nuclear weapons if they choose; sometimes this is a mature capability restrained only by political choice, and sometimes it refers to nations working hard to create the capability that simply have not yet acquired the resources or technological expertise to complete the project. These programs are usually cloaked in secrecy for reasons that will become evident, and lacking access to classified intelligence data, we can only speculate as to who all the threshold nations are, but they probably include at least these:

  • Iran (which makes no secret of its intent)
  • Japan (which has large stockpiles of plutonium from the nuclear power sector and all the required expertise, but so far lacks the political will)
  • Taiwan (which engaged in weapons research until at least the 1970s but is very circumspect about it)
  • Saudi Arabia (concerned with balancing its Iranian rival for Islamic pre-eminence)
  • Brazil
  • Germany

During the Cold War, the NPT had some diplomatic and moral force, backed by international inspections of signatories (but not of those who refused to sign!), but just as significant was the bipolar world order. Many states that were capable of pursuing nuclear weapons independently did not do so, because they were offered the alternative of alliance with either the U.S. or U.S.S.R., which promised them a "nuclear umbrella" of deterrence: a promise to respond with nuclear weapons to any nuclear aggression against them. Those promises either evaporated with the collapse of the Soviet Union, or are considered less than reliable from the United States in recent decades. The end of the Cold War, in this and many other ways, did not mean greater stability and security in the world; in many respects the opposite is true.

So-called "breakout states" are a subset of threshold nuclear states. These are nations that are within weeks or months of deploying usable nuclear weapons; in other words, they have the materials (highly enriched uranium or plutonium) in weapons-ready form, and the plans, expertise, and facilities to assemble reliable, effective weapons very swiftly after a political decision to do so. Breakout status is a major source of instability and risk, and Iran provides an example.

Iran has an active nuclear weapons program. When it reaches the turnover point - sufficient weapons-grade material, technical components, industrial capability and human expertise to assemble workable weapons - it will enter into the most dangerous phase of its whole effort. Iran has repeatedly and explicitly threatened Israel with nuclear destruction. One or a few Iranian nuclear weapons detonated on Israeli soil might achieve that goal. Therefore, Israel has employed diplomacy, espionage, and sabotage in the past to delay and disrupt Iran's nuclear program, the moment of truth may come when Israel learns that Iran has assembled its first nuclear weapon, or is about to do so. At that point, Iran's nascent nuclear capability will be highly vulnerable to Israeli military action, but will have very low odds of a successful nuclear counterstrike. An overt and destructive Israeli military attack on Iran, whether or not it employs Israel's own nuclear weapons, would be diplomatically and economically catastrophic to Israel - which is why it hasn't happened already - yet it would likely be seen as preferable to allowing Iran's nuclear capability to grow and become secure. As soon as Iran has enough weapons dispersed, concealed, and protected against attack, they will be safe from attack, because even one or a few survivors of that attack could effectively destroy Israel, regardless of any damage to the Iranian homeland. A similar logic pertains to any other pair of antagonistic states pursuing their own nuclear weapons capability. Once one of those states as sufficient nuclear weapons in place that some could at least survive an enemy attack, they will have a stabilizing effect. Until that moment, it creates enormous risk.

India and Pakistan made it past that point of extreme instability and risk, deploying nuclear weapons almost simultaneously. Fundamentally hostile to one another since their independence from Britain, they fought four conventional wars before both became nuclear weapon states - but there have been little more than minor border skirmishes since.

Israel's officially "ambiguous" but widely known nuclear weapons capability has prevented major war in since 1973, essentially its "breakout" moment. It fought its Arab neighbors in major conventional wars four times between 1947 and 1973. Since 1973 it has not been attacked by any nation or alliance of nations. The risk is simply too high; some analysts call Israel's nuclear deterrent strategy, which promises nuclear destruction of any attacker that threatens military victory over Israel the "Samson Option," referring to the Biblical figure who collapsed a Philistine temple on himself, killing thousands of his Philistine enemies.

An informal but observable rule has developed since the dawn of the nuclear age in the late 1940s. Nuclear weapons states have not gone to war with one another, despite what might have seemed to them good and compelling reasons. The risk of unintended escalation from conventional conflict to nuclear war through accident or miscalculation is just too great. Many wars were fought between client nations or minor allies of the nuclear superpowers, or in revolutionary struggles, with insurgency and counterinsurgency openly backed by the superpowers. But there was always a degree of separation, keeping the armed forces of two nuclear powers from engaging in open and direct conflict.

That rule appears to have been forgotten or is being willfully ignored by Western leaders in 2022 who urge direct intervention by NATO forces in the war between Russia and Ukraine. Their nations are deeply involved in that war, both in its root causes and in massive support to Ukraine to prolong it, but none of that is unusual in great power politics. However, as of early October, 2022, there is a rising chorus that accuses Russia of planning to employ nuclear weapons in that war, and threatens a nuclear response by NATO. The risks of out-of-control escalation into widespread regional or global nuclear war cannot be overstated, and the lessons of the last 70 years seem to have been forgotten.

Whether over Ukraine, in the Middle East, in the Far East (where nuclear breakout state Taiwan, with a U.S. guarantee of military support, faces a mounting threat of invasion by China), or in a resurgence of belligerence between Pakistan and India, the risk of nuclear war in the near term is high. Unfortunately, none of these flash points is likely to erupt in isolation; the first nuclear attack since 1945 may open Pandora's box.

Nuclear war: a citizen's POV

Two nuclear weapons have been used in war, both against Japan in 1945. Their effect brought a swift end to WW2, by threatening to bring the level of destruction already inflicted on Tokyo and a dozen other cities by conventional bombing, to potentially every city in Japan (although in fact there was only one additional bomb ready for use at the time).

Since then, through the Cold War to the present day, there have been countless scenarios constructed by strategists and war planners. We need to sift through these and consider the number and distribution of nuclear weapons today - not 30 years ago - and the likely objectives of those who might use them. From this emerges a frame of reference for what nuclear war - or wars - might look like in the third decade of the 21st Century. Then we'll get down to the details of weapons effects and countermeasures that individuals, communities, even nations should consider.

Ninety percent of the nuclear weapons in existence today belong to the United States and Russia (successor state to the long-gone Soviet Union), who each have between 5,000 and 6,000, subject to complex rules of counting and classifying weapons deployed and ready for use versus those in deep storage or awaiting disassembly. Those numbers are down from approximately 20,000 and 40,000 respectively at the height of the Cold War, if you are looking for an encouraging point of light in this discussion, thanks to the arms control treaties of the 1980s and 1990s, with which both countries have mostly complied. We couldn't bounce the rubble nearly so high now.

Of the other seven known nuclear weapon states, known inventories are estimated by the Federation of American Scientists as follows (Israeli and North Korean numbers might be significantly higher):

  • UK: 225
  • France: 290
  • Israel: 90
  • Pakistan: 165
  • India: 160
  • China: 350
  • North Korea: 20

The numbers matter. Most of these inventories reflect the basic logic of deterrence: a nation seeks to have sufficient weapons to ensure that enough would survive an enemy first strike to inflict unacceptable damage on the enemy, thereby deterring that attack from ever being made. To some extent that logic reflects the early Cold War strategies of the superpowers, who saw a significant threshold between conventional and nuclear war, and who pictured nuclear war as a spasm of all-out attack and retaliation, or an inevitable escalation from any more limited use until either "escalation dominance" was achieved (i.e., one side cried "uncle" and desisted), or the same all-out exchange occurred. There was in practice not a great deal of confidence in controlling and limiting nuclear weapons use, once it was initiated, so despite high levels of belligerence and distrust at many critical decision points, nuclear war was avoided.

Targeting the adversary's own nuclear forces - which would include air bases, naval installations, and storage facilities where either nuclear weapons or the subs, ships, aircraft and missiles that can deliver them are found - is a likely doctrine in many scenarios, from a small regional nuclear war to a conflict among two or more of the great powers. The underlying assumption is that the enemy will probably not attack with all his weapons at once, so destroying the unused remainder before it can be used is a high priority. Such a strategy does provide the small consolation that a large portion of the nuclear weapons in hand today are targeted on other nuclear weapons, and might destroy or disable them before they could be used. However, the collateral damage to civilian populations and infrastructure would still be enormous.

Some nuclear powers lack accurate, reliable nuclear weapons in sufficient numbers to effectively target an enemy's hard targets; to varying degrees, Britain, France, and China fit this description. Their weapons are likely aimed primarily at soft targets exclusively, threatening large population centers and civilian infrastructure to create the deterrent effect described previously. Nuclear deterrence has always depended upon convincing potential enemies that even if faced with destruction, the nation under attack would respond by devastating the attacker. Strategies based on retaliatory, wholesale destruction of enemy countries and population are known as Mutual Assured Destruction, i.e., both antagonists would be effectively wiped out, no matter who fired first or for what reason. The acronym "MAD" was appropriate, and was memorably satirized with dark humor by Cleavon Little in the film "Blazing Saddles" when his character, facing a lynching at the hands of an angry mob, held his own gun to his head and said, "Next man moves, the n***r gets it!" The ringleaders recoiled in horror: "Hold on, men, he's not bluffing! Listen to him! He's just crazy enough to do it!"

As weapons became more accurate and all critical targets could be reached in a matter of minutes by intercontinental or sea-based missiles, a new threat, the disabling "first strike", began to emerge in the late 1970s. Such a strike, launched without warning, with the benefit of surprise could theoretically destroy the bulk of the other side's nuclear forces before they could be launched in a retaliatory strike - and the ones that did launch might be largely intercepted by the aggressor's defenses, with only a handful actually reaching their targets. The first side might absorb that much damage and actually emerge mostly intact and therefore victorious in a 15- to 30-minute war, its opponent rendered helpless though not destroyed. "Mostly intact" is a relative concept; the Soviet Union had suffered at least 26 million deaths in World War 2 - and still won. However, no one ever attempted a nuclear first strike, because miscalculation or plain bad luck (e.g., the enemy responds more quickly than expected, or has 50 or 500 surviving weapons instead of merely 5 or 10) would turn the war-winning stroke into national suicide.

In today's world, that first strike/disarming strategy may be even less feasible for the US or Russia. Although their arsenals are several times larger than everyone else's added together, they are fewer in number relative to the target set, and therefore less capable than they were during the Cold War of carrying out an effective, war-winning first strike. US and Soviet leadership, after decades of implacable hostility and distrust, in the end saw the lunacy of living that close to the brink of a war of that magnitude. President Reagan called the Soviet bluff, matching their coercive first-strike threat with one of our own, backed by a missile defense concept that the Soviets could not afford to match, and the Soviets blinked - and collapsed.

Before all that happened, though, the strategists remained at work providing more opportunities to do the wrong thing as conditions changed.

The first shift away from the nuclear strategy of MAD arose from the asymmetry of conventional military power between the USSR (and its Warsaw Pact allies) and NATO along the "Iron Curtain" in central Europe. By the 1960s, that balance was weighted in favor of the USSR; both sides believed that Warsaw Pact forces could overwhelm NATO's defenses before reinforcements from the US could stabilize the situation. But no one was confident that, if faced with defeat on the battlefield, the US threat of nuclear response and national suicide would be taken seriously. Instead, a new strategy known as Flexible Response emerged, which called for the use of smaller "tactical" nuclear weapons on the battlefields of West Germany and against deeper targets in Eastern Europe to stop a Warsaw Pact offensive. The Soviet response to this was to plan for use of their own tactical nuclear weapons from the beginning of the war, setting off a competition for dominance on that level. Both superpowers imagined being able to cap the nuclear warfare so that it did not escalate to an exchange of thousands of intercontinental weapons, ensuring the destruction of both nations. That particular competition was finally decisively won by Reagan's commitment to deploy a new generation of US nuclear ballistic and cruise missiles on NATO soil in Europe, that the Soviets could neither match nor defend against.

A similar logic was adopted out of necessity by Russia after the collapse of the USSR at the end of 1991. Russian conventional military strength (and morale) was devastated, its economy was too wrecked to rebuild it, and its new borders after the independence of Belarus, Ukraine, Kazakhstan and other former Soviet republics were indefensible against any plausible threat. Departing from Soviet standards of secrecy and ambiguity, Russia released a series of national strategy declarations starting in 1993 that specifically renounced any previous (Soviet-era) commitments to not initiate the use of nuclear weapons. It reserved the right to use any weapons, including nuclear, that were needed to ensure their national survival. These strategies evolved through several stages - first reinforced by the demonstration of Russian military weakness in Chechnya, and then again in Georgia in 2008. Then, as its conventional military finally improved, its strategy backed off by stages from relying on early resort to nuclear weapons, although the option of initiating their use was never abandoned. US analysts during the Trump administration interpreted this to mean that "… when faced with the likelihood of defeat in a military conflict with NATO, Russia might threaten to use nuclear weapons in an effort to coerce NATO members to withdraw from the battlefield." Although this was a mirror image of US and NATO Flexible Response doctrine of the 1960s-1980s, it was and is cast in a sinister light when invoked by Russia.

Now we have US officials threatening nuclear destruction of all Russian forces in Ukraine, and of their Black Sea Fleet, in response to any Russian nuclear weapon use targeted on Ukraine. The likelihood of provoking a more massive response, and the distinction between treaty-obligated military response in defense of a NATO ally and risking global nuclear war over Ukraine (neither a NATO member nor a US ally), are not understood, or are ignored.

All of this nuclear posturing - "veiled threats" each side says of the other - was common enough during the Cold War, but the context was never active ground combat, even by proxies, directly across US or Russian borders, which takes the current situation to an unprecedented level of risk.

That scenario may be the most dangerous, because it could end with the US in a state of war with Russia, depending upon cooler heads to prevail before conventional or nuclear combat escalates to a "use them or lose them" mass exchange of weapons between our respective homelands. Only Russia has any capability to attack and destroy our own nuclear weapons, and only Russia could be tempted to try it, and would arguably do so if facing what they considered an existential threat themselves.

The second greatest threat is in the western Pacific, where direct combat between Chinese and US forces is possible if China initiates its long-promised invasion of Taiwan to force that "breakaway province" into submission. China, with 10% or less of the US nuclear arsenal, cannot risk a major nuclear exchange but might be confident of forcing the US to back out of a war over Taiwan by use of a few nuclear weapons against US Pacific bases like Guam or US naval task forces in the region. They might consider a nuclear response by the US to be unlikely, and they would probably be correct. However, they have non-nuclear forces that are capable of striking the same targets with a high confidence of success, so why risk a nuclear exchange? The farthest such a conflict would conceivably go - by intention, assuming no miscalculations or mistakes - might be a "demonstration" attack somewhere on American soil, either our Pacific island territories, Alaska, Hawaii, or the mainland; although that would represent uncharacteristically rash behavior by China.

Direct nuclear attacks on American forces, territory, or vital interests from other sources are very unlikely, unless it were an EMP attack, a subject we will return to later in our discussion of nuclear weapons effects.

Regional nuclear wars foreseeable at this time would probably not directly affect the United States, unless our forces were engaged or close enough to be affected. Depending on the number of weapons detonated, their locations and circumstances, and global weather patterns, there might be significant fallout and would almost certainly be major disruptions in the global economy, supply chains, and food and fuel supplies - as if those are not already in a crisis state.

Nuclear terrorism - the detonation of a nuclear weapon by a terrorist organization - is another possibility although so far unrealized. It would be difficult and expensive to plan, stage, and execute, and if the perpetrators have a return address - if they can be tracked to a supportive nation state - that nation might just as well have launched an open, direct nuclear attack, because the retaliatory response would probably be the same. Other forms of mass-casualty terrorism remain much more likely. These forms include chemical, biological, radiological dispersion devices, conventional explosives, or just a bunch of guys with rifles (e.g., Beslan or Mumbai).

Nuclear weapon effects

We won't dive into the scientific and engineering aspects, and we won't buy into the hand-wringing apocalyptic terror of the anti-nuclear crowd (old and new alike) - the "I just hope I'm at ground zero so I'll die fast" nonsense. Instead, we'll discuss what a nuclear weapon does, and a little about targeting and scenarios, not from an academic or even national security perspective, but in terms of what it means to us as individuals, families, and communities.

Initial and residual effects

Nuclear weapon effects are divided into initial (mostly confined to the first minute after detonation) and residual. 90-95% of the initial energy release is in the form of blast and thermal radiation, with only the remaining 5-10% being nuclear radiation. Residual nuclear radiation, mostly in the form of fallout, can continue for days or weeks depending on the height of the burst above ground level and other considerations.

Explosive yield

Nuclear weapons are ranked by "yield" or the explosive energy they release when detonated, expressed as the equivalent in TNT. The fission bomb dropped on Hiroshima in 1945 had an estimated yield of 15 kilotons, the equivalent of 15,000 tons of TNT. Later technological developments led to "boosted" fission weapons with yields up to ten to twenty times greater, and to fission-fusion weapons with yields in the megaton range (a million tons of TNT), the largest being the Soviet "Tsar Bomba," a one-off device that produced a yield of 50 megatons in a test, but was never produced or deployed; and the US Mark 17 with a yield of 10-15 megatons, briefly deployed in small numbers in the 1950s.

To make a long story short, in addition to the number of nuclear weapons having declined since the height of the Cold War in the 1960s and 1970s, most of those deployed today have much lower yields - 500 kilotons or less, many of them much less. The change was mostly due to an improvement in missile accuracy, which allowed hits within 100 meters of the target, or less, even at intercontinental range. This made it possible to plan the destruction of even a very "hard" target like a missile silo or underground command center with a much lower-yield weapon. There is considerable added expense and no real advantage in using a weapon many times more powerful than needed. Even against soft targets, it was realized that multiple smaller weapons were actually more efficient than a single very large one.

Burst height

Another important determinant of nuclear weapon effects is the altitude of the detonation.

A weapon can detonate as an air burst, usually several thousand feet above ground level, which maximizes the radius of the blast and thermal effects and - if the fireball does not touch the ground - reduces the amount of radioactive fallout. This would be the favored method against soft targets like civilian populations, ports, industry, transportation nodes, or military targets like troop concentrations or air bases.

It is important to understand that direct civilian casualties were often considered a "collateral" effect of nuclear weapons use, but not the primary objective. This does not necessarily mean nuclear war planners were a kinder, gentler sort than their Strangelovian popular image, because the indirect (non-nuclear) effects of a large-scale nuclear attack would be horrendous enough: the loss of power, water, food, and medical services would cause casualties dwarfing the direct effects of the weapons, albeit over weeks and months rather than seconds and minutes.

Weapons which detonate very close to ground level or below it are called ground or subterranean bursts. Their surface blast and thermal radiation is less than an air burst; they generate large amounts of fallout by picking up, irradiating and dispersing large quantities of soil, rock, and other ground level materials; and they create powerful subterranean shock waves effective against underground bunkers, command centers, or missile silos that are well-protected against surface blast and heat effects. The missile silos around Malmstrom AFB at Great Falls, Montana or F.E. Warren AFB at Cheyenne, Wyoming would attract multiple ground bursts for this reason.

As noted previously, if a warhead was too inaccurate to hit close enough to an underground hard target, it had to have a much higher yield to destroy it. Until the last decade of the Cold War, Soviet warheads aimed at our missile bases were some of the highest-yield weapons ever widely deployed, because they were relatively inaccurate. To destroy a Minuteman ICBM in its silo, or a squadron cluster of ten of those around their launch control center) a very powerful shock wave was required, travelling through the ground from a massive detonation on or below the surface. That shock wave could be created by a 5-megaton warhead detonating a kilometer from the target, or a 150-kiloton warhead 100 meters away. A missile might carry one of the large warheads, or 5-10 of the smaller ones. More was better, because redundancy was important. Missile defenses might destroy some warheads, but not all; some might go astray, detonate early, or not detonate at all. It was prudent to target any high-value target with multiple warheads - it's the only way to be sure.

So many surface/subsurface bursts would make survival problematic anywhere nearby and for potentially hundreds of miles downwind, because of the massive, deadly fallout plume generated by so many ground or subsurface detonations. This is a significant factor in considering the overall risks and hazards in a major nuclear exchange.

Initial nuclear radiation

Radiation is of course the boogieman in most people's picture of nuclear weapons effects, but it is often overrated, at least as far as initial effects. An airburst by a weapon in the high kiloton range would maximize blast and thermal effects, causing immediate casualties over a radius determined by the explosive yield of the weapon, and the nature of the terrain and structures within that radius.

However, weapons of that size or larger - ten or more times the yield of the bombs dropped on Japan - will cause initial, lethal nuclear radiation within a smaller radius than that of the blast overpressure and thermal effects. If you were close enough to receive a lethal dose of radiation, you would probably die of blast injuries (overpressure collapsing your lungs, or being thrown into hard objects or hit by flying debris) or from the thermal effect (burns and superheated air), before the radiation dose would even be noticed. Beyond the lethal blast radius, initial radiation effects decline very rapidly. Not to minimize the experience of the citizens of Hiroshima or Nagasaki, but most of those who died in those attacks were killed by blast and thermal effects not very different from those experienced by the citizens of Tokyo (or Dresden, or many other Axis cities) under Allied conventional bombing in 1944-45.

How to avoid the initial effects of a nuclear detonation

So much for immediate blast, thermal, and radiation effects. If you are more than a few miles from a typical nuclear ground or airburst, your likelihood of being either killed or seriously injured by the initial effects is small. The best advice may be:

a) Minimize the time you spend that close to a likely target; or

b) If you sense a very bright white flash, immediately close and cover your eyes to save your vision from temporary or permanent damage, and drop behind the most solid form of cover within immediate reach - ideally a ditch, berm, concrete or masonry wall or building - and away from windows. The thermal effect moves barely slower than the speed of light, but duration matters, so even a second or two gained could limit its effect to that of a bad sunburn or less, at a few miles' distance. The blast wave is much slower, and at these distances, there will be time to minimize your exposure to flying, shattered glass and other airborne, dangerous debris. Pressure and velocity of the blast wave at several miles from ground zero (the point on the ground over which the detonation is centered) will be on the order of magnitude of a tornado or tropical storm, and similar protective measures could save you from serious injuries. The immediate radiation at a distance of several miles will be minimal and survivable. The old "Duck and Cover" drill taught to school kids was not nearly as foolish as it seems.

Fallout: residual nuclear radiation

Fallout is the dispersal of radioactive particles into the atmosphere, where they are typically carried some distance by the wind, and eventually fall to earth, where their radioactivity can be dangerous for variable periods of time. Some radioactive isotopes present in fallout have a very long half-life (i.e., remain dangerous for a long time), like Strontium 90, which was widely dispersed in fallout from above-ground nuclear testing in the 1950s and early 1960s, and was picked up in the food chain to appear in dairy products for years after. Most radioactive isotopes in fallout, however, decay very rapidly. Common Cold War-era advice to civilians in an area under a fallout plume from upwind was to stay in a concrete, earth, or masonry-built shelter stout enough to stop penetrating radiation and with a filtered air supply and adequate stores of food, water, and other essentials, for at least two weeks. After two weeks, most fallout outside would have decayed to the point that brief exposures would not be too hazardous; but the longer you could stay in shelter, the safer you would be upon emergence.

A very useful and affordable measure you can take is to stockpile tablets of potassium iodide, and take a full dose over the first few weeks of potential fallout exposure. Radioactive iodine is a common component of fallout, and iodine compounds accumulate in the thyroid gland. Harmless potassium iodide saturates the thyroid gland so that any radioactive iodine taken into the body is excreted with minimal exposure and damage. However, it does not protect you from other radioactive effects from exposure to fallout; that protection depends upon time (length of exposure), distance, and shielding.

If you are not directly downwind of nuclear detonations, you should not be exposed to a great deal of fallout. Fallout will typically reach several thousand feet in altitude, be carried downwind from the detonation for tens or possibly hundreds of miles, falling to earth along that path, which may be wider or narrower, and irregularly shaped, by differences in wind strength and direction. A fraction of the fallout, especially from high altitude air bursts that don't produce much fallout anyway, can rise into the stratosphere, where it is more widely dispersed and descends much more slowly and in lower concentrations. That high-altitude fallout, after anything less than a large-scale exchange of hundreds or thousands of weapons, would probably result in nothing more than a small but perceptible rise in cancer rates over a period of decades, comparable to the nuclear power disasters at Chernobyl and Fukushima.

Finally, we must mention what may actually be the most likely form of nuclear attack the United States might suffer: an EMP, which stands for Electromagnetic Pulse, and specifically a High-Altitude EMP. We will give it a more in-depth treatment elsewhere, but it needs to be mentioned here because it involves the detonation of a nuclear weapon, or perhaps several of them, at very high altitudes (likely 150-200 miles above sea level) where all the direct effects described in this article (except potential eye injury if it occurs at night) would be negligible. It would look like a small, very bright, and very swift flash in the sky. An enemy targeting the United States would likely want to ensure complete and overlapping coverage of North America by detonating at least three devices, one over the geographic center of the country, and one each over the East and West coasts. The effects, in brief, would be a powerful, invisible, and instantaneous electromagnetic pulse or field propagating through all types of antennas and conductive materials, which would devastate the national electric grid and disable most solid-state electronic devices, including most computers, phones, and wired or wireless communications. Sober estimates of the effect of such a strike include a fatality rate of up to 90% of the US population in the subsequent year due to the crippling of vital infrastructure and industries. We mention it here because it is in fact an attack using nuclear weapons. Although even our military systems are at present inadequately shielded against EMP, at the very least, several US nuclear missile armed submarines deployed at sea would likely be unaffected, and might, if they could determine the source of the attack, strike back with nuclear missiles. Depending on many variables, a spasm of more "conventional" nuclear warfare might follow, and spread.

Scale and Scope

Nuclear war, if it does occur, may not approach the magnitude of the effects predicted and imagined during the Cold War, or alluded to here. It may be regional or limited in its scope and duration. The number of weapons available is far fewer than at the height of the Cold War, and as was the case then, most of the existing weapons are trained upon each other, and the number that would survive to be launched and detonated would always be fewer than the nuclear warriors intend. It might not include any nuclear detonations in the U.S., and might be limited to an exchange of a few tens of weapons between antagonists such as Israel and Iran, or Pakistan and India. Even at such a small scale, however, the effects on the global economy would be significant and that's not just about money and trade; the potential for extended war, displaced populations, famine, and pandemic disease could dwarf the direct effects of a brief nuclear conflict. It would also be a figurative opening of Pandora's box: the first post-1945 nuclear war might not be the last.

Actions

If you haven't considered it previously, consider your location. Sources referenced below can help you calculate your proximity to high value targets and your exposure to fallout from targets upwind of you. Reduce your vulnerability by relocation if you can, or if not, then have a plan, preparations, and a secure, capable means of travel to get out of danger areas before, during, or after a nuclear attack.

Whether or not you are in a likely fallout plume, give some thought to fallout protection, which can be achieved with affordable (and unobtrusive) modifications to masonry structures, basements, safe rooms, storm shelters, or root cellars. Your preparations should include stockpiles of food, water, other necessary expendables, tools, and all necessary items for two weeks or more of isolation from the outside world, and for the conditions you might find upon emergence.

One of the first casualties of any nuclear weapons use will be disruption in communications and information. If you have not already, ensure you have some means of communications outside your immediate area, for the purpose of collecting information and intelligence to maintain your situational awareness. HAM (amateur) radio is an excellent capability, but at least, maintain one or more shortwave radio receivers disconnected and protected against EMP, with a survivable source of power: batteries and a charging capability.

As we've already noted, the second and third order effects of anything but the most limited and short-duration nuclear war could be as serious as any of the other macro-scale events we've addressed in our Threat Assessment, Community Defense, and other discussions. Prepare yourself, your family, and your community for long term survival under extreme conditions.

Since the Internet may be an early casualty of nuclear warfare, we recommend the following hard-copy resources - among many others - for study, prior preparation, and guidance in the aftermath:

The Effects of Nuclear Weapons, Department of the Army Pamphlet No. 50-3, HQ, Department of the Army: March 1977.

Nuclear War Survival Skills: Lifesaving Nuclear Facts and Self-Help Instructions, Cresson H. Kearny, Skyhorse Publishing, New York: January 2016.

EMP: Protect Family, Homes and Community, Don White & Jerry Emanuelson, Renewable Energy Creations LLC, 2013.

Strategic Relocation: North American Guide to Safe Places, 3rd Ed., Joel M. Skousen & Andrew Skousen, Printing Resources, Lindon, UT, 2010.