Instead of challenging the legal basis of the strike, the institutions we regard as “checks” on the president have simply fawned and simpered.

Military force is dangerous; its lawless use is even more dangerous. The constitutional and statutory constraints on the war power, as interpreted in practice over the past 75 years, already afford a president broad leeway to send American forces into harm’s way; but Trump has now blown past the few constraints that remain.

And nobody is calling him on that.

President Trump, after watching televised footage of a gas attack on the rebel-held city of Khan Sheikhoun, ordered U.S. forces to strike at a Syrian Air Force base. That was not an attack on the United States. Trump did not request authorization from Congress. He also did not seek authorization from the United Nations Security Council; he did not consult with the NATO allies who have been supporting U.S. military operations elsewhere in the Middle East.

Let’s be clear about the strike against Syria. It is not and cannot be part of the ongoing “war” the U.S. is waging against the successors of the Taliban and Al Qaeda. Syria’s armed forces aren’t part of Al Qaeda or any of its successors; the 2001 Authorization for the Use of Military Force doesn’t cover Syria. By launching missiles against Bashar al Assad’s military, Trump was crossing an important legal line.

Under the Constitution, the crossing of that line must, either at the time or soon afterwards, involve both of the “political branches” of the government—Congress and the President. Tiresome as it may be to reminded of this, Article I § 8 cl. 11 gives to Congress, not the President, the power “to declare war””—that is, to begin hostilities against another country. The President is designated by Article II § 2 cl. 1 as “commander in chief” of the armed forces. By implication—and, from what we can tell from the founding-era materials, by design—this gives a president power to respond to emergencies and what James Madison called “sudden attacks.” This, however, is a narrow, temporary exception to Congress’s plenary power over war and peace, not a backdoor to full-scale warfare.

Some people believe War Powers Resolution changes this constitutional calculus—“giving” the President power to commit military forces for up to 60 days. It doesn’t. The Resolution in its first section repeats that the president’s commander-in-chief powers are properly “exercised only pursuant to (1) a declaration of war, (2) specific statutory authorization, or (3) a national emergency created by attack upon the United States, its territories or possessions, or its armed forces.” The 60-day limit is an additional limit, not a blank check for short wars.

In a War Powers letter to Congress, Trump said, “I directed this action in order to degrade the Syrian military’s ability to conduct further chemical weapons attacks and to dissuade the Syrian regime from using or proliferating chemical weapons, thereby promoting the stability of the region and averting a worsening of the region’s current humanitarian catastrophe. I acted in the vital national security and foreign policy interests of the United States, pursuant to my constitutional authority to conduct foreign relations and as Commander in Chief and Chief Executive.”