The conflict between Israel and Iran has shaped the Middle East for decades. It was largely on a low boil as the two sides attacked each other — mostly quietly and in Iran’s case often by proxy — while avoiding a full-blown war.

The United States would bear legal responsibility in the event of an Israeli attack on Iranian nuclear facilities, Foreign Minister Abbas Araqchi said on Thursday, following a CNN report that Israel might be preparing strikes on Iran.

Iran’s nuclear facilities are deep underground and heavily fortified. An effective attack by Israel would require U.S. assistance for both mid-air refueling and munitions, according to the February intelligence report.