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.

Whether the U.S. gets more involved than it already is, some members of Congress from both parties argue, should not be up to the President.

Israel and Iran both have little incentive to stop and no obvious route to outright victory. Much depends on President Trump.