The killing of Qassim Soleimani in Baghdad on Thursday was a lawful act, wholly compatible with President Trump's responsibilities as commander in chief. Trump had no obligation to consult Congress before ordering the operation which killed the leader of Iran's Islamic Revolutionary Guard Corps.

Others disagree.

Sen. Chris Murphy observed that "Soleimani was an enemy of the United States. That’s not a question. The question is this — as reports suggest, did America just assassinate, without any congressional authorization, the second most powerful person in Iran, knowingly setting off a potential massive regional war?"

Murphy's implication, echoed by House Speaker Nancy Pelosi, is that Trump required congressional approval to kill Soleimani. More absurd was United Nations Special Rapporteur on Extra-Judicial Executions Agnes Callamard's ranting failure to recognize that the U.S. has a right to self-defense.

But, as usual, the U.N. is rather irrelevant here. So let's focus on Congress.

The first point to note is that there are legitimate and necessary debates over the president's executive authority in conducting longer-term military operations. The executive branch is also legally obliged to brief members of the congressional intelligence committees, or at least a smaller group of eight senior congressional leaders, on any ongoing covert actions.

But while there is at least one major U.S. covert action program on Iran, the legal notice requirements weren't triggered by the separate Soleimani killing. That's because this action was overt and narrowly defined in scope.

More importantly, there is a long tradition of government attorneys, the courts, and Congress deferring to presidents where they deem it necessary to use force to address a serious, near-term threat to U.S. security. Sometimes there is an existing congressional authority for these actions, such as the post-Sept. 11 authorization that encompassed the operation to kill Osama bin Laden.

But that authorization isn't necessary where a credible near-term threat exists, and that was certainly the case with Soleimani.

After all, when it comes to murderous plots against Americans and critical American interests, the evidence file against Soleimani is broad, deep, and unequivocal. For just one example, Soleimani orchestrated a failed 2011 plot to bomb the Saudi Ambassador and dozens of people dining in a Washington, D.C., restaurant. When that attack agent warned his handler that the explosion might kill 100 innocent Americans, the officer responded, "F--- 'em."

This is who Soleimani was: a committed, highly capable, and ideologically vested enemy of the U.S. And as the Pentagon statement on his death suggests, Soleimani was almost certainly plotting new attacks against American interests when he was killed.

Iran is escalating against American interests in a desperate effort to blackmail Washington into granting sanctions relief. But the legal context that ultimately matters most is the condition of Soleimani's ongoing threat.

That threat was severe. As commander in chief, Trump had obvious authority to address it.