When Donald Trump threatened to “totally destroy North Korea” at the United Nations General Assembly a year ago, the declaration sent shock waves through Washington, where there has never been much of an appetite for war in East Asia—even within the Republican Party. This year, however, the Trump administration is delivering a message to the world leaders and diplomats who descended upon New York City’s far east side for the annual gathering that is assured to strike a positive chord within the G.O.P. ranks: it’s us or Iran. U.S. Ambassador to the U.N. Nikki Haley warned that the Europeans have “a decision to make,” because “We’re going to be really tough on Iran. We’re not giving them a pass.” During his address on Tuesday, Trump decried what he characterized as Iran’s “corrupt dictatorship,” that “sow[s] chaos, death and destruction.” And Secretary of State Mike Pompeo declared Iran to be “truly an outlaw regime,” adding that it “is therefore incumbent on every country to join our efforts to change the regime’s lawless behavior.”

But it was John Bolton who drove the message home in a bellicose address on Tuesday. While speaking to a friendly audience at an event hosted by United Against Nuclear Iran—an organization that opposed the Obama-era nuclear deal, from which Trump withdrew in May—the national security adviser warned that Iran would face “serious consequences” if it doesn’t fall in line with the U.S. “According to the mullahs in Tehran, we are ‘the Great Satan,’ lord of the underworld, master of the raging inferno,” Bolton told the audience. “So, I might imagine they would take me seriously when I assure them today: If you cross us, our allies, or our partners; if you harm our citizens; if you continue to lie, cheat, and deceive, yes, there will indeed be hell to pay.” He went on to deride the 2015 nuclear deal as “the worst diplomatic debacle” in America history. “The United States is not naive. We will not be duped, cheated, or intimidated. The days of impunity for Tehran and its enablers are over,” he said. “The murderous regime and its supporters will face significant consequences if they do not change their behavior. Let my message today be clear: we are watching, and we will come after you.”

For Bolton, who once penned an op-ed titled, “To Stop Iran’s Bomb, Bomb Iran,” such rhetoric is not surprising. Neither is his opposition to the 2015 agreement between the five permanent members of the U.N. Security Council—the U.S. the United Kingdom, France, Russia and China—plus Germany and the European Union. Bolton’s distaste for multilateralism is well-documented. In a 1994 speech, years before he was named U.S. ambassador to the U.N., he infamously said that if the organization’s headquarters lost 10 stories “it wouldn't make a bit of difference.” His influence on Trump in this regard has not gone unnoticed. “There is a clear pro-sovereignty, anti-multilateral entity that is coming out of the president at new heights, I think because of John Bolton,” Sarah Margon, the Washington director of the Human Rights Watch, said in reference to Trump’s address on Tuesday.

But in his role as national security adviser to Trump, who campaigned on an anti-intervention platform, Bolton’s saber-rattling feels misplaced. As John Glaser, the director of foreign-policy studies at the Cato Institute noted, “Bolton’s unrestrained threat inflation was truly reminiscent of the Bush administration’s war bombast in the lead up to the 2003 invasion of Iraq. He and Pompeo, in particular, are unabashedly recycling the same hackneyed regime-change rhetoric that accompanied one of America’s most shameful and calamitous foreign-policy blunders.” Notably, Bolton remains an unrepentant and unabashed supporter of the 2003 Iraq invasion. But as recently as last week, Trump characterized George W. Bush’s decision to go into the Middle East as “The worst single mistake ever made in the history of our country.”