If Trump wants to smash Mexican cartels, he's got history and law on his side

With Puerto Vallarta and the state of Jalisco under siege from the cartels, American policymakers need to know that President Donald Trump would be on strong legal ground if he chooses to hit the cartels in Mexico or anywhere in the world.

Over the last four decades, the drug cartels have transported tens of thousands of military-age men over our borders, many of them carrying weapons of mass destruction like fentanyl or carfentanil. This isn’t "migration." It’s an invasion, and, under the Constitution...