Over the past few months, President Trump has deployed an imposing military force in the Caribbean to threaten Venezuela. Until now, the president used that force — an aircraft carrier, at least seven other warships, scores of aircraft and 15,000 U.S. troops — for illegal attacks on small boats that he claimed were ferrying drugs. On Saturday, Mr. Trump dramatically escalated his campaign by capturing President Nicolás Maduro of Venezuela as part of what he called “a large scale strike” against the country.

Few people will feel any sympathy for Mr. Maduro. He is undemocratic and repressive, and has destabilized the Western Hemisphere in recent years. The United Nations recently issued a report detailing more than a decade of killings, torture, sexual violence and arbitrary detention by henchmen against his political opponents. He stole Venezuela’s presidential election in 2024. He has fueled economic and political disruption throughout the region by instigating an exodus of nearly eight million migrants.

If there is an overriding lesson of American foreign affairs in the past century, however, it is that attempting to oust even the most deplorable regime can make matters worse. The United States spent 20 years failing to create a stable government in Afghanistan and replaced a dictatorship in Libya with a fractured state. The tragic consequences of the 2003 war in Iraq continue to beset America and the Middle East. Perhaps most relevant, the United States has sporadically destabilized Latin American countries, including Chile, Cuba, Guatemala and Nicaragua, by trying to oust a government through force.

Mr. Trump has not yet offered a coherent explanation for his actions in Venezuela. He is pushing our country toward an international crisis without valid reasons. If Mr. Trump wants to argue otherwise, the Constitution spells out what he must do: Go to Congress. Without congressional approval, his actions violate U.S. law.