President Trump has emerged as the king of terrorist designations. During less than a year in office, he has added more groups to the State Department's Foreign Terrorist Organization list than any other administration did over four years. He has expanded the definition of terrorists beyond ideologically based outfits to include smuggling cartels and nation-hopping gangs such as MS-13 and Tren de Aragua, whose motivation is more about money or power than about the desire to terrorize. Mr. Trump is focused on the ends, not the means. He says the tens of thousands of Americans slain by fentanyl each year far outstrip the deaths caused by radical Islamic attacks, so groups that traffic the drugs deserve the full force of terrorism law.