Sen. Lindsey Graham (R-SC) revealed Saturday that, after a discussion with President Donald Trump, he was “completely convinced” of what the president’s next move may be regarding the ongoing U.S. war against Iran, and one that could potentially involve a “massive military operation.”“I just had a great conversation with [Trump]. I totally support his ultimatum to the Iranian regime to open up the Strait of Hormuz and to do a peace deal,” Graham wrote Saturday in a social media post on X. “A massive military operation awaits Iran if they choose poorly.”The Trump administration has struggled to achieve any of its objectives in its war against Iran, which have included toppling the Iranian government and removing its capabilities of acquiring a nuclear weapon. Since the war began in late February, reopening the Strait of Hormuz – a critical shipping lane once accessible to U.S.-aligned vessels – has emerged as a new key objective of the war, one that has also, so far, eluded the Trump administration.Trump has warned Iranian officials that if they continue to block U.S.-aligned vessels from accessing the Strait of Hormuz, that the U.S. military would soon escalate its targeting of civilian infrastructure, including bridges, power plants and water-treatment plants, actions that would likely constitute war crimes.After his conversation with Trump, Graham appeared convinced that Trump was fully prepared to make good on his threats.“After speaking with President Trump this morning, I am completely convinced that he will use overwhelming military force against the regime if they continue to impede the Strait of Hormuz and refuse a diplomatic solution to achieve our military objectives,” Graham wrote. “If it’s not clear to Iran and others by now that President Trump means what he says then I don’t know when it will ever be. Choose wisely.”I just had a great conversation with @POTUS. I totally support his ultimatum to the Iranian regime to open up the Strait of Hormuz and to do a peace deal. A massive military operation awaits Iran if they choose poorly. This regime has been severely crippled through Operation…— Lindsey Graham (@LindseyGrahamSC) April 4, 2026