President Trump returned to Washington on Tuesday to deal with the war between Iran and Israel, as the two sides exchanged deadly fire for a fifth day and Israeli officials pressed the United States to join its military campaign against Tehran.

Initially planned to last up to three weeks, according to Israeli assessments, US involvement could dramatically shorten the conflict’s duration.

"Israel is being assisted this way or that way by some Iranians," ex-Israeli National Security chief Giora Eiland told Newsweek.

The group is one of the most powerful and shadowy arms of Iran’s military, and it has long been on the front line of a shadow conflict with Israel.

Israel had prepared for the possibility that the war could last for weeks, but that timeline may now be shortened.

Iran and Israel targeted each other with airstrikes early on Saturday after Israel launched its biggest-ever offensive against its longtime foe in a bid to prevent it from developing a nuclear weapon.

Aerial attacks between Israel and Iran continued overnight into Monday, marking a fourth day of strikes following Israel's Friday attack. That surprise strike hit the heart of Iran's nuclear program,