The first use of nuclear weapons occurred Aug. 6, 1945. The second occurred three days later. That there has not been a third is testimony to the skill and sobriety of 12 presidents and many other people, here and abroad. Today, however, North Korea’s nuclear bellicosity coincides with the incontinent tweeting, rhetorical taunts and other evidence of the frivolity and instability of the 13th president of the nuclear era. His almost daily descents from the previous day’s unprecedentedly bad behavior are prompting urgent thinking about the constitutional allocation of war responsibilities, and especially about authority to use U.S. nuclear weapons.

Last month, for the first time in 41 years, a congressional hearing examined the Atomic Energy Act of 1946 that gives presidents sole authority. There was serious discussion of whether a particular presidential order for their use might not be “legal” — necessary, proportionate. But even if, in a crisis, time permits consulting lawyers, compliant ones will be found: President Obama’s argued that the thousands of air strikes that killed thousands and demolished Libya’s regime did not constitute “hostilities.”

The exigencies of crisis management in an age of ICBMs require speed of consultations, if any, and of decisions. And the credibility of deterrence requires that adversaries know that presidents can act in minutes. Furthermore, the authority to employ nuclear weapons is, as was said at the congressional hearing, “intertwined” with the authority “to take the country to war.” So, as a practical matter, President Trump can unleash on North Korea “fire and fury” without seeking the consent of, or even consulting, Congress. This, even if North Korea has neither attacked nor seems about to attack America. A long train of precedents tends to legitimate — although not justify — practices, and this nation has engaged in many wars since it last declared war on June 5, 1942 (when, to satisfy wartime legalities, it did so against Hungary, Bulgaria and Romania). Over many decades, Congress has become — has largely made itself — a bystander regarding war.

Sen. Lindsey Graham, R-S.C., says, “If we have to go to war to stop this, we will.” By “this” does he means North Korea’s possession of nuclear weapons, which it has had for 11 years? Or ICBMs, which it is rapidly developing? If so, Graham must think war is coming, because there is no reason to think that North Korea’s regime will relinquish weapons it deems essential to its single priority: survival. As Vladimir Putin says, North Korea would rather “eat grass.” U.S. actions have taught this regime the utility, indeed the indispensability, of such weapons. Would America have invaded Saddam Hussein’s Iraq if he had possessed them? Would America have participated in destroying Libya’s regime in 2011 if, soon after Saddam’s overthrow, Moammar Gadhafi had not agreed to abandon his nuclear weapons program?

North Korea, says Trump, is a “situation we will handle” — “we will take care of it.” Does “we” denote deliberative and collaborative action by the legislative and executive branches? Or is “we” the royal plural from the man whose general approach to governance is, “I alone can fix it”? Trump’s foreign policy thinking (“In the old days, when you won a war, you won a war. You kept the country”; we should “bomb the shit out of [ISIS]”) is short on nuance but of Metternichian subtlety compared to his thoughts on nuclear matters: “I think, for me, nuclear is just the power, the devastation is very important to me.”

A U.S. war of choice against North Korea would not be a pre-emptive war launched to forestall an imminent attack. Rather, it would be a preventive war supposedly justified by the fact that, given sophisticated weapons and delivery systems, imminence might be impossible to detect. The long war on the primitivism of terrorists has encouraged such thinking. A leaked 2011 memo from the Obama administration’s Justice Department argued that using force to prevent an “imminent” threat “does not require … clear evidence that a specific attack … will take place in the immediate future.” So, regarding al-Qaida, the memo said that because the government might not know of all plots and thus “cannot be confident that none is about to occur,” any leader of al-Qaida or “associated forces” can be lawfully targeted at any time, without specific knowledge of planned attacks.

It would be interesting to hear the president distinguish a preventive war against North Korea from a war of aggression. The first two counts in the indictments at the 1946 Nuremberg trials concerned waging “aggressive war.”

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