Shapiro served as Deputy Assistant Secretary of Defense for the Middle East until January—charged with, among other things, considering scenarios in which tensions between Israel and Iran escalated into all-out war and preparing U.

Despite stunning early successes in Israel’s unprecedented strikes on Iran, a weekend of intensive bombardment and retaliation is raising questions about Israel’s exit strategy – how it can end this conflict with its ambitious goals achieved.

Iran has vowed to retaliate against the U.S., too, while Trump has warned: “If we are attacked in any way, shape, or form by Iran, the full strength and might of the U.S. Armed Forces will come down on you at levels never seen before.” Here’s what to know about U.S. involvement so far.