Sen. Lindsey Graham said Monday that the US should attack Iran if the Islamic Republic followed through on threats against Americans or America’ s interests.

“The fault lies with the Iranians, not the United States or any other nation. If the Iranian threats against American personnel and interests are activated we must deliver an overwhelming military response,” Graham tweeted. “Stand firm Mr. President.”

The South Carolina Republican, one of the president’s most dutiful supporters, fired off his bellicose tweet after getting a briefing from National Security Adviser John Bolton, an Iran hawk who has long argued for regime change in the country.

“Just received a briefing from National Security Advisor Bolton about escalating tensions with Iran. It is clear that over the last several weeks Iran has attacked pipelines and ships of other nations and created threat streams against American interests in Iraq,” he tweeted.

Several international vessels were sabotaged in recent weeks, and the White House has pointed the finer at Iran, which backs several militias involved in military conflicts in the region.

Trump recently sent an aircraft carrier and other military resources to the Persian Gulf region, and withdrew nonessential personnel from Iraq, raising alarm among Democrats and some Republicans on Capitol Hill over the possibility of a military confrontation with Iran.

Trump in recent days downplayed any potential for conflict, though he warned Sunday that the US could destroy the country if provoked.

“If Iran wants to fight, that will be the official end of Iran. Never threaten the United States again!” he wrote on Twitter.

But questions remain about what prompted the actions and many lawmakers have demanded more information.

House Democrats will hear from former CIA director John Brennan — a harsh Trump critic — about the situation in Iran on Tuesday.

Trump and Brennan, who stepped down from the CIA in 2017, have clashed openly, particularly over the issues surrounding the special counsel’s probe of Russian interference in the 2016 election.

The president last year said he was revoking the former spy chief’s security credentials after Brennan was critical of Trump’s deferential interactions with Russian President Vladimir Putin at a summit in Helsinki.

Top national security officials often retain their clearance after they have left an agency as a way to provide counsel to their successors.

It’s unclear if Brennan actually lost his clearance.

House Speaker Nancy Pelosi had been asking the administration for a briefing for all lawmakers on the situation in Iran, but she said the request was initially rebuffed.

The administration provided a classified briefing for top leaders of both parties last week.

Many lawmakers and US allies were skeptical of the administration’s claims that Iran posed a heightened threat to the US.

With AP