The successful operation against Qassem Suleimani, head of the Islamic Revolutionary Guard, is a stunning blow to international terrorism and a reassertion of American might. It will also test President Trump’s Iran strategy. It is now Trump, not Ayatollah Khamenei, who has ascended a rung on the ladder of escalation by killing the military architect of Iran’s Shiite empire. For years, Iran has set the rules. It was Iran that picked the time and place of confrontation. No more.