Although different administration officials (and supporters) have said different things publicly and on social media throughout the day on Saturday, the basic legal argument appears to be that the military operation was in support of the extraterritorial criminal arrests of the Maduros.

The basis for that argument is the merger of two strands of legal arguments that have long been made by the Department of Justice—but never blessed by the Supreme Court. The first strand traces to a deeply controversial 1989 DOJ Office of Legal Counsel memorandum by then-Assistant Attorney General Bill Barr (yes, the same one), which concluded that the President has inherent constitutional authority to use the FBI for extraterritorial arrests, even in circumstances in which the arrests violate international law (e.g., by infringing upon a foreign nation’s sovereignty). The memo also concluded, quite … usefully, that such arrests don’t violate the Fourth Amendment. The second strand is DOJ’s longstanding view that the President has inherent constitutional authority to use military force to protect federal institutions and officers in the exercise of their federal duties. Thus, in a textbook example of the tail wagging the dog, the military force was merely the means by which President Trump “protected” the handful of FBI personnel who apparently were involved in the actual arrests.

Question #2: Okay, So Why Are Those Arguments Unpersuasive?
Without attempting to be exhaustive, it seems to me that there are at least three things to say about these arguments:

First, note how any reliance upon the Barr Memo is giving up the ghost on the (obvious) violations of Venezuela’s sovereignty—and, thus, the U.N. Charter (to say nothing of myriad other international agreements and precepts of customary international law). There’s no attempt to even try to argue that this operation was consistent with international law—for the obvious reason that … it isn’t. (There had been some suggestion earlier in the day that the Trump administration might try to identify Venezuelan officials who had “invited” the United States to breach Venezuela’s sovereignty, but that … hasn’t gone anywhere.) Thus, unlike the boat strikes, which have all occurred in the legally grayer area of international waters, Friday night’s operation involves a textbook violation of foreign sovereignty for which the Trump administration’s principal response appears to be “whatever.”

Second, it is the epitome of bootstrapping to use the idea of “unit self-defense” as the basis for sending troops into a foreign country so that a handful of civilian law enforcement officers can exercise authority they wouldn’t be able to exercise but for the military support. My friend and former State Department lawyer (and Cardozo law professor) Bec Ingber has written in detail about why the “unit self-defense” argument is effectively a slippery slope toward all-out war, and she’s right. It seems just as important to point out that the U.S. constitutional law argument seems just as limitless. If Article II authorizes the use of military force whenever a foreign national living outside the United States has been indicted in a U.S. court, that could become a pretext for the United States to use military force almost anywhere—in circumstances that could easily (and quickly) escalate to full-fledged hostilities. Something tells me the Founders, who were deeply wary of military power, would not exactly see this as consistent with what they wrote—at least until and unless Congress had done something to authorize, or even acquiesce in, these kinds of distinctly offensive military operations.

Third, and perhaps most importantly, the closest relevant historical precedent for this episode—the U.S. invasion of Panama in December 1989 (Operation “Just Cause”), which resulted in the deposing and arrest of Manuel Noriega—is distinguishable in one critical respect: In the Panama example, the Panamaian general assembly had formally declared a state of war against the United States, and a U.S. Marine had been shot and killed, before President George H.W. Bush authorized the underlying operation. And even then, there’s still nothing approaching consensus that Operation Just Cause was actually consistent with U.S. law; Congress passed no statute authorizing hostilities, and it was hard to see how the situation in Panama posed any kind of imminent threat to U.S. territory sufficient to trigger the President’s Article II powers—just like the Trump administration’s narco-trafficking claims seem difficult to reconcile with where fentanyl actually comes from (Mexico) or the Trump administration’s own behavior (like pardoning former Honduran president-turned-cocaine-trafficker Juan Orlando Hernández). In other words, the only real precedent for what happened Friday night doesn’t provide any legal support for the United States’ actions.