Trump’s Iran strikes mark his biggest foreign policy gamble

With his large-scale attack on Iran, Donald Trump has seized a legacy-defining moment to demonstrate his readiness to exercise raw U.S. military power. But in doing so, he is also taking the biggest foreign policy gamble of his presidency, one fraught with risks and unknowns.

Trump joined with Israel to plunge into war against Iran, and after a day of air strikes announced on Saturday that Supreme Leader Ayatollah Ali Khamenei had been killed, which would mark a major achievement for...