This morning, President Trump unilaterally launched a regime-change war against Nicolás Maduro of Venezuela, ordering strikes on multiple military targets in the country and seizing its leader and his wife. They were “captured and flown out of the country,” Trump stated on Truth Social.After Pearl Harbor, Franklin D. Roosevelt addressed Congress and asked it to declare war on Japan. Prior to waging regime-change wars in Afghanistan and Iraq, George W. Bush sought and secured authorizations to use military force. Those presidents asked for permission to conduct hostilities because the supreme law of the land, the Constitution, unambiguously vests the war power in Congress. And Congress voted to authorize force in part because a majority of Americans favored war.Trump says he will speak to the nation at 11 a.m. eastern time and address his rationale for the attack. The president may point to the fact that the State Department has branded Maduro the head of a “narcoterrorist” state, and that in 2020 Maduro was indicted in the United States on charges that he oversaw a violent drug cartel. For months Trump has been seeking the ouster of Maduro, and aligning the United States with opposition figures who contest the legitimacy of his presidency.But these accusations and the indictment wouldn’t seem to constitute legal justification. Overnight, multiple members of Congress pointed out that Trump’s new war is illegal because he received no permission to wage it, and it was not an emergency response to an attack on our homeland or the imminent threat of one.The probable illegality of Trump’s actions does not foreclose the possibility that his approach will improve life for Venezuelans. Like too many world leaders, Maduro is a brutal thug, and opposition figures have good reason to insist he isn’t the country’s legitimate leader. I hope and pray his ouster yields peace and prosperity, not blood-soaked anarchy or years of grinding factional violence.But “toppling Maduro is the easy part,” Orlando J. Pérez, author of Civil-Military Relations in Post-Conflict Societies, warned in November. “What follows is the hard strategic slog of policing a sprawling, heavily armed society where state services have collapsed and regime loyalists, criminal syndicates, and colectivos—pro-government armed groups that police neighborhoods and terrorize dissidents—all compete for turf.” Two groups of Colombian militants “operate openly from Venezuelan safe havens, running mining and smuggling routes,” he added. “They would not go quietly.”If those challenges are overcome, Trump may lack the leadership qualities necessary for long-term success. Now that the United States has involved itself this way, its leaders are implicated in securing a stable postwar Venezuela and in staving off chaos that could destabilize the region. Yet Trump is best suited to military operations that are quick and discrete, like the strikes on Iranian general Qasem Soleimani or Iran’s nuclear sites, as they do not require sustained focus or resolve. He is most ill-suited, I think, to a regime change war against a country with lucrative natural resources. I fear Trump will try to enrich himself, his family, or his allies, consistent with his lifelong pattern of self-interested behavior; I doubt he will be a fair-minded, trusted steward of Venezuelan oil. If he indulges in self-dealing, he could fuel anti-American resentment among Venezuelans and intensify opposition to any regime friendly to the United States and its interests.Another problem confronting Trump as he goes to war is that his political coalition, and indeed his cabinet is divided between interventionists and noninterventionists. “The United States needs to stay out of Venezuela,” Tulsi Gabbard, his Director of National Intelligence, declared in 2019. “Let the Venezuelan people determine their future. We don't want other countries to choose our leaders—so we have to stop trying to choose theirs.”Whether the outcome is ultimately good for Venezuelans, as I hope, or bad, Trump has betrayed Americans. He could have tried to persuade Congress or the public to give him permission to use force. He didn’t bother. He chose war despite polls that found a large majority of Americans opposed it. Perhaps, like me, they fear America is about to repeat the mistakes of its interventions in Afghanistan, Iraq, and Libya, where brutal regimes were ousted, then ruinous power vacuums followed.“I look forward to learning what, if anything, might constitutionally justify this action in the absence of a declaration of war or authorization for the use of military force,” Senator Mike Lee, a Republican of Utah, posted.But the real question isn’t whether this action was legal, it is what to do about its illegality. Ignoring the law and the people’s will in this fashion is a high crime. Any Congress inclined to impeach and remove Trump from office over Venezuela would be within their rights. That outcome is unlikely unless Democrats win the midterms. But Congress should enforce its war power. Otherwise, presidents of both parties will keep launching wars of choice with no regard for the will of people or our representatives. And antiwar voters will be radicalized by the dearth of democratic means to effect change.War-weary voters who thought it was enough to elect a president who called the Iraq War “a stupid thing” and promised an “America first” foreign policy can now see for themselves that they were wrong. In 2026, as ever, only Congress can stop endless wars of choice. And if Trump faces no consequences for this one he may well start another.