It seems President Trump has aroused heightened interest in the exercise of Congress’s constitutional powers in war and peace. In a 366–30 vote this week, the House of Representatives passed a nonbinding resolution declaring the U.S. military’s role in Saudi Arabia’s war in Yemen unauthorized. That’s a start. Even more promisingly, a growing group of Senate Democrats is pushing legislation that would prohibit any use of funds for “military operations in North Korea absent an imminent threat to the United States without express congressional authorization.”

Though it merely makes more explicit something that ought to be fully understood under the Constitution, sponsors of the bill have understandable motivations here. President Trump has repeatedly claimed that he does not need Congressional authorization to initiate military action. In April, he demonstrated his commitment to this unlimited view of presidential war powers when he ordered missile strikes against a Syrian airbase in the absence of any credible claim of preemption and without legal authorization from Congress.

Two months earlier, the president gave an indication that he would not seek Congressional authorization or approval in potential military action against North Korea. In a press conference in February, when asked about it, he insisted, “I don’t have to tell you what I’m going to do in North Korea.”

In the ensuing months, the president has exacerbated the tensions between the United States and North Korea. In addition to taunting and ridiculing via his Twitter account, Trump has also made bold public threats. “North Korea best not make any more threats to the United States,” he told reporters in August, or “they will be met with fire and fury like the world has never seen.”

Adding to the heightened tensions, National Security Advisor H.R. McMaster has gone so far as to say the regime in Pyongyang is undeterrable. This is remarkably out of step with what the bulk of the academic literature says on the question, but it is also destabilizing in that the logical conclusion of such an assessment is that we must initiate a full-scale attack on North Korea. After all, if Pyongyang possesses nuclear weapons and doesn’t care about regime survival, traditional deterrence isn’t an option.

Senator Bob Corker (R‑TN), who, as chair of the Senate Foreign Relations Committee would be the one to shepherd the legislation to a vote, said last month that Trump is treating the presidency like “a reality show,” and his rhetoric could set the nation “on the path to World War III.” To the extent that Trump’s advisors act as a check on the president’s erratic foreign policy inclinations, Corker added, they “separate our country from chaos.”

This escalatory rhetoric occurs in the context of a broad understanding that an outbreak of war on the Korean Peninsula would be catastrophic. Secretary of Defense James Mattis warned grimly on CBS’s Face the Nation that, “A conflict with North Korea would probably be the worst kind of fighting in most people’s lifetimes…it would be a catastrophic war if this turns into a combat if we’re not able to resolve this situation through diplomatic means.”

Scholarly and official estimates bear this out. Even a limited conventional strike by the United States against North Korean nuclear sites would risk an overwhelming number of casualties because Pyongyang’s likely response would be to immediately attack Seoul with the roughly 8,000 artillery cannons and rocket launchers positioned along the border capable of unleashing 300,000 rounds on South Korea in the first hour of the counterattack. The result would be massive destruction and hundreds of thousands of casualties in a matter of days.

And that’s if it doesn’t go nuclear, which it almost inevitably would if Pyongyang, fearful of its own destruction, found itself under attack by the world’s most powerful military. If the Kim regime targeted Seoul and Tokyo with just one nuclear weapon each, casualties would approach almost 7 million. And again, this would only generate additional escalation from all parties.

At this point, even the most cynical proponent of war would be hard pressed to identify what political end could possibly justify such devastation.

The bizarre thing about the focus on the military option is that there are plenty of worthwhile diplomatic options. American diplomats who have engaged in back-channel negotiations with North Koreans for years have made clear Pyongyang remains interested, so long as talks are conducted on the basis of mutual respect and mutual compromise, instead of demands for one-sided capitulation. Avenues include short-term confidence-building measures, like a “freeze for freeze” deal in which Pyongyang halts its nuclear weapons testing in exchange for a freeze of U.S.-South Korean joint military exercises, which the North sees as provocative. Grander bargains are also possible, but it requires a willingness on both sides to choose compromise and accommodation over rigidity and vainglory.

Explicit Congressional action prohibiting the Trump administration from initiating preventive war against North Korea may aid in checking executive war powers in this case. But only maybe. Much depends on whether the administration chooses to rely on unreasonably elastic definitions of the phrase “imminent threat.” And at the end of the day, legal constraints only have utility if the people subject to them respect them. Hopefully, the costs and risks associated with escalation will prove enough of a constraint.