The dilemma of whether the US should join Israel in attacking Iran, or stay out of the offensive altogether, has exposed divisions among US President Donald Trump's supporters.
The Republican president reportedly is considering helping target the Islamic Republic's nuclear facilities, following a meeting with his national security advisers in the White House Situation Room on Tuesday.
On the campaign trail, Trump often railed against "stupid endless wars" in the Middle East, but also maintained that Iran "can't have a nuclear weapon".
The possibility that he might draw the US into another foreign entanglement has pitted the isolationist and hawkish wings of his party bitterly against one another.
On Tuesday, conservative Republican congressman Thomas Massie of Kentucky sided with Democrats to introduce a bill that would block Trump from engaging US forces in "unauthorised hostilities" with Iran without congressional approval.
