Trump's Nuclear Button and International Law

Before the closing ceremonies of the Winter Olympics on Sunday, South Korea’s president announced that North Korea is interested in a diplomatic dialogue with the United States. 

The welcome news comes after a year of extraordinary tensions between Washington and Pyongyang. Since Donald Trump took office in January 2017, North Korea has engaged in a record number of provocative actions, including test launching intercontinental ballistic missiles capable of striking the United States  and test detonating a hydrogen bomb.  In response, President Trump has threatened to “totally destroy” North Korea in the event of war.  Moreover, the president declared earlier this month that his “nuclear button” is “much bigger & more powerful” than Kim Jong Un’s “nuclear button.”  No previous American president has ever publicly threatened to use nuclear weapons in such a brazen and flippant way.

The nuclear standoff between North Korea and the United States raises a fundamental question of international law: Do the laws of war permit the use of nuclear weapons?

In most cases the answer is no. Any detonation of nuclear weapons in the vicinity of urban centers would violate two cornerstone laws of war: the prohibition on indiscriminate warfare and the prohibition on the targeting of non-combatants. But the question becomes much murkier when the proposed use of the weapon is in an area far removed from civilian populations, such as a tactical nuclear strike on a remote missile facility in the mountains. In such a scenario, the laws of war are remarkably unclear.   

Basic Law of War Principles 

Although international law expressly bans chemical and biological weapons,  there is no international treaty that bans nuclear weapons. In fact, in a 1996 advisory opinion, the International Court of Justice expressly rejected the notion that customary law prohibits the use of nuclear weapons. In an 11-3 ruling, the court held that “[t]here is in neither customary nor conventional international law any comprehensive and universal prohibition of the threat or use of nuclear weapons as such.”  

The upshot of the ICJ’s ruling is that the use of nuclear weapons is governed by traditional law of war principles just like any other weapons system. In other words, strange though it may seem, under international law a 5-megaton nuclear warhead is analyzed under the same principles as a 50-pound conventional bomb.

Nevertheless, despite the lack of an international treaty that expressly regulates the use of nuclear weapons, there are three general prohibitions in the laws of war that effectively render most—but not necessarily all—uses of nuclear weapons unlawful.

The first is the prohibition on the intentional targeting of non-combatants. Under international law, combatants may never target non-combatants. A nuclear attack on a city for the purpose of destroying the civilian population is thus a clear-cut violation of the laws of war. That means a North Korean nuclear attack on American cities—or an American nuclear attack on North Korean cities—would  unquestionably violate the laws of war.

The second is the prohibition on indiscriminate attacks. A fundamental principle of the laws of war is that attackers must make a reasonable effort to distinguish between combatants and non-combatants. If the attacker fails to distinguish between combatants and non-combatants, then the attack is unlawful, regardless of whether the attack is conventional or nuclear in nature.  The ban on indiscriminate warfare is particularly crucial in the context of nuclear weapons, which by their very nature inflict indiscriminate destruction on a massive scale.

The Hiroshima and Nagasaki Examples

History provides a grim illustration of how the first two cornerstone principles of the laws of war apply to nuclear weapons. The only country to use nuclear weapons in wartime is the United States. In August 1945, during the final days of World War II, the United States attacked the Japanese cities of Hiroshima and Nagasaki with atomic bombs, attacks that killed a combined total of more than 100,000 civilians. In addition, thousands of Japanese civilians suffered from horrific burn wounds and radiation sickness. 

Although the laws of war were not fully developed in 1945, international law as it exists today would deem the Hiroshima and Nagasaki attacks clear-cut war crimes.

First, the United States specifically intended to kill Japanese civilians on a massive scale for the purpose of shocking the Japanese government into surrender. Hiroshima and Nagasaki thus constituted textbook examples of the intentional targeting of non-combatants, which is the most heinous war crime of all. 

Second, even if we accepted the completely implausible and untenable argument that the atomic bombs were “merely” intended to destroy Japanese military facilities in Hiroshima and Nagasaki, the American attacks were still unlawful (at least under the current laws of war) because they were indiscriminate in nature. The United States detonated the atomic weapons about 2,000 feet above the Japanese cities, creating blast waves that simultaneously and indiscriminately killed and injured combatants and non-combatants alike. To put it mildly, no effort was made by the United States military to distinguish Japanese combatants from Japanese non-combatants. Consequently, the atomic bombs employed against Hiroshima and Nagasaki were by their very nature “indiscriminate” in character, and therefore undeniably unlawful under the modern law of armed conflict.

The Collateral Damage Conundrum

The illegality of using nuclear weapons in urban areas is thus clear. But is any use of nuclear weapons permissible under international law?

The answer, at least arguably, is yes. In the preeminent textbook on the laws of war, The Conduct of Hostilities under the Law of International Armed Conflict,  Prof. Yoram Dinstein points out two potentially lawful uses of nuclear weapons: a nuclear strike on an army convoy in a vast desert far from civilian populations, and a nuclear strike on navy vessels in a remote location in the ocean. In both cases, the targets would be lawful, and the risk to non-combatants would be low. After explaining the legal dimensions of the question, Dinstein emphasizes in his book the inherently destabilizing implications of using nuclear weapons, observing: “All States members of the nuclear club are soberly aware of the colossal ramifications of a decision to unleash these cataclysmic weapons.”

But that point may no longer be so certain. President Trump’s long-standing fascination with nuclear weapons makes it much more conceivable that the United States might actually use nuclear weapons in a confrontation with North Korea. Indeed, as President Trump’s boastful reference to his “nuclear button” suggests, it is at least within the realm of possibility that—in the event of open conflict with Pyongyang—Trump might order a limited, tactical nuclear strike against remote North Korean mountain bases suspected of harboring ICBMs or hydrogen bombs.

The tactical strike scenario implicates a third cornerstone law of war principle: proportionality. International law prohibits attacks that are likely to cause disproportionate “collateral damage," a euphemistic term for unintended death and destruction inflicted on non-combatants. Collateral damage is not inherently unlawful. The critical legal question in such cases is whether the anticipated collateral damage is “excessive” in relation to the military necessity of the attack. In addition, even if the expected collateral damage is proportional to the military necessity of the attack, the attacker must take reasonable precautions to minimize the likely harm to non-combatants.

The problem, however, is one of evidence. The task of proving that collateral damage is "disproportionate" to the military necessity of the attack is exceedingly difficult. The terms “military necessity” and “proportionality” are so subjective and so vague that successful prosecutions for “excessive” collateral damage are few and far between. As Prof. Valerie Epps argued in an important law review article, the collateral damage rule has proven so ineffective that it is almost a dead letter.

The collateral damage issue would be raised because even in a remote location, there would inevitably be at least some civilians killed in the general area by the detonation of a nuclear weapon. But it seems likely that in the event of a tactical nuclear strike on a remote North Korean missile base, the Trump Administration would argue that the “military necessity” of destroying North Korea’s nuclear weapons program is proportional to the anticipated collateral damage caused by the attack. The North Koreans would of course disagree, but there is no objective measure for resolving such a dispute.

The bottom line, therefore, is if President Trump used nuclear weapons against Pyongyang or other North Korean cities, the attack would clearly be unlawful. The same would also be true of a North Korean attack on American cities.

But if President Trump used tactical nuclear weapons against North Korean missile or weapon facilities in remote parts of the country, the laws of war provide very little clarity on whether such an attack would be lawful.

The legal issues notwithstanding, one point should be clear: any use of nuclear weapons would have dangerously destabilizing effects that would be impossible to contain. Presidents have understood that crucial point since at least 1949, when the Soviets developed an atomic bomb of their own, thus ushering in the nuclear arms race of the Cold War era. But whether President Trump understands the destabilizing consequences of using nuclear weapons is a disturbingly open question.   

The 1980 ICBM Explosion in Arkansas

Even assuming a peaceful resolution of the U.S.-North Korea standoff is achieved, the mere existence of nuclear weapons poses a significant risk to all countries that have them.

Last year PBS’s American Experience program aired a chilling documentary  on the most serious nuclear missile accident in American history. In September 1980 a U.S. Air Force maintenance crew at an underground launch silo in Arkansas accidentally punctured the fuel tank of a Titan II nuclear missile with a 9-megaton warhead onboard. As it became clear that the missile would eventually explode, the Pentagon faced the appalling possibility that the warhead would detonate and destroy much of Arkansas and Missouri.

In riveting and unforgettable fashion, the documentary relates what happened before, during, and after the missile explosion.

Although I don't recommend watching it before going to bed, the documentary, which is based on Eric Schlosser’s important and timely book on the subject, Command and Control: Nuclear Weapons, the Damascus Accident, and the Illusion of Safety,  is available on YouTube.  It provides a sobering reminder of how profoundly dangerous it is for humans to possess nuclear weapons, let alone use them.

Comments

[Patrick S. O'Donnell]

Many thanks for this helpful and indeed urgent post.

Let’s not forget that the U.S. destroyed more than sixty Japanese cites prior to the atomic bombing of Hiroshima.

Nor should we forget the fact that both the Nuremberg and Tokyo war crimes tribunals were held in cites obliterated by Allied bombing “yet [these tribunals] famously shielded the victorious powers.” One reason: “Aerial bombardment had been uses so extensively and ruthlessly on the Allied side as well as the Axis side [the Allies the more ‘successful’ of the warring parties at urban destruction] that at neither Nuremberg nor Tokyo was the issue made a part of the trials.”

While it is true that between 1932 and 1945 Japan bombed Shanghai, Nanjing, Chongqing and other cities, “testing chemical weapons in Ningbo and throughout Zhejiang and Hunan provinces,” the following additional historical facts are often (intentionally or not) ignored:

“Throughout 1943-44, [the U.S.] tested firebombing operations against Japanese homes, finding that M-69 bombs were highly effective against the densely packed wooden structures. In the final six months of the war, the United States threw the full weight of its airpower into campaigns to burn whole Japanese cities to the ground and terrorize, incapacitate, and kill their largely defenseless residents in an effort to force [the regime to] surrender.”

Let’s not forget as well the role of one Curtis Emerson LeMay (1906 – 1990), “a general in the United States Air Force and [later] the vice presidential running mate of American Independent Party candidate George Wallace in the 1968 presidential election. LeMay is credited with designing and implementing an effective, but also controversial [to put it mildly if not feely], systematic strategic bombing campaign in the Pacific theater of World War II.”

“LeMay was the primary architect, a strategic innovator, and most quotable spokesman for U.S. policies of putting enemy cities, and later villages and forests, to the torch, from Japan to Korea to Vietnam. In this he was emblematic of the American way of war that emerged from World War II.” Of course Le May did not act in isolation, being a master link in a “chain of command extended upward through the Joint Chiefs of Staff to the President.”

Let’s recall, once again (well, for those of us familiar with it), some of the particulars of this shameful history:

“The full fury of firebombing and napalm was unleashed on the night of March 9-10, 1945, when LeMay sent 334 B-29s low over Tokyo from the Marianas. Their mission was to reduce the city to rubble, kill its citizens, and instill terror in the survivors, with jellied gasoline and napalm that would create a sea of flames. [….] The attack, on an that the U.S. Strategic Bombing Survey estimated to be 84.7 percent residential, succeeded beyond the wildest dreams of air force planners. Whipped by fierce winds, flames generated by the bombs leaped across a fifteen-square mile area of Tokyo, generating immense firestorms that killed scores of thousands of residents. [….] Nature reinforced man’s handiwork in the form of akakaze, the red wind that swept with hurricane force across the Tokyo plain and propelled firestorms that drove temperatures up to 1,800 degrees Fahrenheit, creating superheated vapors that advanced ahead of the flames, killing or incapacitating their victims. ‘The mechanisms of death were so multiple and simultaneous—oxygen deficiency and carbon monoxide poisoning, radiant heat and direct flames, debris and the trampling feet of stampeding crowds—that causes of death were later hard to ascertain….’ [….]

While the deaths, estimated by both Japanese and American authorities at the time to be roughly around 100,000 (with perhaps a million more wounded and another million left homeless), “it is [given the number of people who lived in the burned-out areas and the ‘near total inability to fight fires of the magnitude produced by the bombs’] possible to imagine that casualties may have been several times higher than the figures presented on both sides of the conflict. [….]

Following the attack, LeMay, never one to mince words, said that he wanted Tokyo ‘burned down—wiped right off the map’ to ‘shorten the war.’ Tokyo did burn. Subsequent raids brought the devastated area to more than 56 square miles, provoking the flight of millions of refugees.”

The bombing strikes were extended to yet more cities in Japan, as “bombing strikes destroyed 40 percent of the 66 Japanese cities targeted with total tonnage dropped on Japan increasing from 13,800 tons in March to 42,700 tons in July. If the bombing of Dresden produced a ripple of public debate in Europe, no discernible wave of revulsion, let alone protest, took place in the United States or Europe in the wake of the far greater destruction of Japanese cities and the slaughter of civilian populations on a scale that had no parallel in the history of bombing. [….]

Between January and July 1945, the United States firebombed and destroyed all but five Japanese cities, deliberately sparing Kyoto, the ancient imperial capital, and four others. The destruction ranged from 50 to 60 percent of the urban area in some cities, including Kobe, Yokohama, and Tokyo, to 60 to 88 percent in seventeen cities, to 98.6 percent in the case of Toyama. In the end, the Atomic Bomb Selection Committee chose Hiroshima, Kokura, Niigata, and Nagasaki as pristine targets to display the awesome power of the atomic bomb to Japan and the world and send a powerful message to the Soviet Union.” [....]

Throughout the spring and summer of 1945, the air war in Japan reached an intensity that is perhaps still unrivaled in the magnitude of human slaughter. That moment was a product of technological breakthroughs, American nationalism, and the erosion of moral and political scruples about killing of civilians, perhaps intensified by the racism that crystallized in the Pacific theater.” The quoted material is from the chapter by Mark Selden in the book below edited by Tanaka and Young.

One still hears in both public and academic fora “arguments” that attempt to morally justify the dropping of atomic bombs on Japan. These arguments have lost all plausibility, for a host of reasons, some of the best of which are canvassed in Tsuyoshi Hasegawa’s chapter, “Were the Atomic Bombings of Hiroshima and Nagasaki Justified?” in the (extremely important) volume edited by Yuki Tanaka and the late Marilyn B. Young, Bombing Civilians: A Twentieth-Century History (New Press, 2009), as well as Gar Alperovitz’s The Decision to Use the Atomic Bomb (Alfred A. Knopf, 1995). See too the indispensable work by Joseph Gerson, Empire and the Bomb: How the U.S. Uses Nuclear Weapons to Dominate the World (Pluto Press, 2007).

Finally, readers may find sufficient reason to consult my fairly comprehensive bibliography for nuclear weapons that is found on my Academia(dot)edu page.

[Anthony Gaughan]

Thank you so much for your comments, Patrick. And thank you for the great citations to the relevant scholarship!

[Deep State Special Legal Counsel]

Our President is one brave hombre. He will be the new Slim Pickens.

[Prof. Kevin Heller]

Anthony,

You say at two places in the post that the laws of war are unclear about the legality of the remote nuclear strike. Yet as you present them the answer doesn't seem difficult to discern all. You suggest that, at worst, a remote nuclear strike might kill a few civilians. Is proportionality really that difficult to apply in a situation where a high-value military target is attached and a few civilians are incidentally killed? If anything, your post demonstrates that the laws of war are so clear that we have to imagine a highly implausible attack to discuss a situation in which the use of nuclear weapons would be lawful.

[Anthony Gaughan]

Kevin,
Thank you so much for your comments. I absolutely agree with your analysis from a theoretical perspective. In the abstract, it’s certainly true that if the military necessity of the attack is high, and the amount of anticipated collateral damage is low, then the proportionality analysis is relatively straightforward.

But the problem, of course, is that the modern battlefield rarely affords such clarity.

For example, the first problem is I simply do not believe that we can assume that a US tactical strike in North Korea will kill only “a few civilians.” In the abstract, we can certainly imagine a scenario of a remote military base with no civilians around for hundreds of miles.

But in all likelihood, military bases require at a minimum hundreds of civilian support workers, who in turn usually have families, which thus means that there are likely to be thousands of civilians in the general area, at least within commuting distance of the base, even in a remote area.

At what point would those civilian deaths become “disproportionate” to the military necessity of the attack? Would 100 deaths be too many? Would 1,000? Would 5,000? No international criminal tribunal has ever told us what the answer to that question is.

The second problem is assessing the “military necessity” of the attack. Military commanders routinely disagree over the military necessity of particular operations. For example, one commander may see an attack as vital, whereas another commander may see the attack as totally unnecessary. Indeed, the history of warfare is in large part a history of generals disagreeing with each other over strategy and tactics.

Compounding the problem is the fact that military intelligence, by its very nature, is almost never conclusive. It offers probabilities, not certainties.

The Bin Laden raid in 2011 is a classic example.

Before the raid was launched, President Obama and his top advisers were not even sure that Bin Laden had ever even been to the compound in Abbottabad. In fact, according to CIA Director Leon Panetta, the CIA estimated that there was somewhere between a 40 and 60% chance that Bin Laden was at the compound.

Accordingly, the president’s top advisers were divided over what kind of raid (if any) should be launched. Most, including Vice President Biden, advocated an air strike, which would have destroyed the whole neighborhood, likely killing large numbers of civilians.

An air strike had many advantages, including reducing the risk of mission failure because of a helicopter malfunction (as, ironically, did indeed happen during the raid) and reducing the risk that the noise of the approaching US forces would alert Bin Laden and give him time to get away. The air plan thus required the use of heavy ordinance in order to not only destroy the compound but also to instantaneously collapse any tunnel network that existed underneath the compound. Indeed, the experience at Tora Bora in 2001 had made clear that Bin Laden was skilled at escaping at the last second from U.S. forces.

But President Obama nevertheless chose (rightly, in my view) to launch a much more dangerous and risky SEAL raid because he believed that it was essential that the U.S. forces seize Bin Laden’s body. Obama thought it critical that the administration be able to confirm that they had in fact succeeded in killing (or capturing) the Al Qaeda leader.

However, imagine if the Biden plan had been implemented instead, and the U.S. Air Force had launched multiple heavy bombs into the compound, completely destroying it and any potential tunnel network underneath it. Not only would there likely have been hundreds of civilian casualties in the surrounding neighborhood, but we also would never have known whether Bin Laden was even there, because his body would have been incinerated in the blast.

Under that scenario, how could we ever assess with legal certainty the “military necessity” of the raid? We wouldn’t know whether Bin Laden was ever there, so we wouldn’t really know whether the attack was necessary or not. Is a 40% chance that he was there sufficient to justify hundreds of civilian deaths?

Also, how do we assess whether it was “reasonable” for Obama to rely on the CIA assessment. In 2003 the US intelligence community notoriously misjudged Saddam Hussein’s WMD program (or, more precisely, his lack thereof).

Any use of nuclear weapons—even in a remote area—is going to create exactly the same problem. Even the most “limited” nuclear attack would completely vaporize the target, leaving no evidence of what was there before the attack.

The inevitable result would be a dispute between the warring powers over what the nature of the facility was (before it was destroyed). The North Koreans will claim it was something innocuous (like Saddam Hussein’s “baby milk factory” during the 1991 Baghdad raids), whereas the White House will adamantly insist that the base was an ICBM launch facility.

Compounding the problem is the fact that the U.S. will never produce the intelligence it relied on because to do so would divulge sources and methods. Moreover, even if it did produce the intelligence reports, the intelligence would likely just come in the form of a “confidence range” offered in percentage terms, like the 40 to 60% range in the Bin Laden case.

And if all that weren’t confounding enough to the legal analysis, we would also face the problem of determining the actual amount of collateral damage incurred in the attack. After all, any use of nuclear weapons will leave virtually no evidence behind of how many people lived in the base’s vicinity prior to the attack. The US will undoubtedly claim few if any non-combatants were there, whereas the North Koreans will claim large numbers of non-combatants were present. In the absence of a pre-attack census, how would we know?

So I absolutely agree with you in the abstract, that if we can say with confidence that the target is a high value military objective, and the collateral damage is low, then there is no problem applying proportionality analysis. But I just don’t think that’s the way things really work on the battlefield.

In any case, thanks again so much for your comments, Kevin! This is such an important issue.

[Anthony Gaughan]

In fairness to the historical record, I should add that it is not certain that Vice President Biden advocated the air strike option or opposed the SEAL raid. There have been conflicting stories regarding what exactly he advised the president to do, including from Biden himself.

For example, Biden initially said that he opposed the SEAL raid. But more recently he said that he was non-committal and simply told the president to "trust his instincts."

The same has happened with other advisers. The initial accounts indicated that many advisers shared Biden's concern about the risks associated with the SEAL raid (including Defense Secretary Gates), but more recently it looks like a majority of Obama advisers now assert that they supported the SEAL raid.

[Deep State Special Legal Counsel]

I have read all of your posts^^^and they are astute and on point. Like I was back in college. Here is the problem. Half the country elected a Silly, Silly man as president who treats nuclear war as a Staples Easy Button. "Now that was easy." He purportedly watches a lot of TV. My solution is this: Show our new man of steel one of those Bell System scientific film strips on a movie projector depicting graphic images of people brunt like toast from a nuclear disaster. One of those Dr. Research (Frank Baxter) films...with the melancholy music... Its not real to Trump if he sees things on a Tablet or You Tube. He is a pretty simple guy.

[Anthony Gaughan]

Thank you for your comment, Deep State Special Legal Counsel. I appreciate it very much!

[Andrew Carter]

I would argue a fourth way that both treaty law and customary international law renders most nuclear weapons use unlawful: the prohibition on the use of environmental modification techniques as a weapon to change the dynamics, composition and structure of the earth.

[Anthony Gaughan]

That's a great point, Andrew. I agree.