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.

If we are attacked in any way, shape or form by Iran, the full strength and might of the US Armed Forces will come down on you at levels never seen

Israel and Iran traded fire for a third straight day on Sunday, with rising casualties and expanding targets marking a sharp escalation in the conflict between the longtime adversaries.

Experts suggest the U.S. has a strategic opportunity to leverage Iran's weakened position for a nuclear deal after Israel's targeted strikes on Iranian nuclear and military sites.

The United States is the main international backer of Israel, Iran's biggest regional foe. It is also a close ally of Sunni Gulf monarchies which for years pursued their own rivalry with the Islamic Republic, seeing it as their main regional threat.

In sweeping attacks that started early Friday, Israel has struck at the regime in Tehran, targeting Iranian nuclear and military assets. The Israeli strikes have killed more than 70 people, including four top security chiefs, and damaged Iran’s main nuclear site at Natanz.

Iran launched dozens of ballistic missiles toward Israel on Friday night in retaliation for Israel's surprise attack early Friday. Israel struck at the heart of the Iran's nuclear program, killing several nuclear scientists as well as high-ranking military leaders, according to Israeli officials.

The United States has pulled some diplomatic staff and military families out of the Middle East, citing unspecified regional security risks.

Israel's operation against Iran is projected to last "weeks, not days," with implicit US approval, according to White House and Israeli officials.