What Trump's new national security adviser means for Iran and North Korea

President Donald Trump’s surprise announcement Thursday to replace his national security adviser H.R. McMaster with John Bolton is not only part of a broader shakeup but represents a shift toward an increasingly hawkish foreign policy posture as he faces major decisions within weeks on North Korea and Iran.

Bolton has a well-established reputation as a hard-liner, often advocating military action over diplomacy — including most recently as a high-profile contributor on conservative-leaning FOX News, a Trump favorite.

Bolton served in both previous Bush administrations, as UN ambassador and Under Secretary of State for Arms Control and International Security - and during that time strongly supported the 2003 invasion of Iraq.

Robert Malley, who served on the National Security Council during the Obama and Clinton administrations, says Trump's choice of Bolton amounts to nails in the coffin for the President Barack Obama’s landmark foreign policy achievement, the Iran nuclear deal.

Bolton has been vocal in advocating for tearing up the deal, an idea that President Trump has also expressed support for even as he has stopped short of withdrawing from the deal thus far.

Bolton is joined in opposing the Iran deal by CIA director Mike Pompeo, the president's nominee to replace Rex Tillerson, an Iran deal supporter, as secretary of state.

“All signs have been pointing toward a likely decision by President Trump to withdraw from an agreement that was working,” Malley said. “I think the dismissal of Secretary Tillerson with Mike Pompeo was a sign that the deal was probably dead and I think the replacement of H.R. McMaster by John Bolton is a sign that the deal is not just dead, but dead and buried.”

Malley remains hopeful that European nations who are partners in the Iran nuclear deal may be able to prop up the agreement with Iran, even without U.S. participation. But if not, Malley worries that the alternative options hold dangerous implications for global security.

“If we’re tearing up this deal … we will be in a situation where either Iran will continue its nuclear program because they’ll no longer be constrained by the deal or the U.S. will decide, along with some of our allies, that we’re going to stop it militarily,” Malley predicts.

And at a time when Trump is staking out a softer path for diplomacy with North Korea by accepting an invitation to sit down for direct talks with Kim Jong Un, Bolton has struck a very different tone in arguing that there is a legal case for a pre-emptive strike against North Korea.

“It is perfectly legitimate for the United States to respond to the current ‘necessity’ posed by North Korea’s nuclear weapons by striking first,” Bolton wrote in a Wall Street Journal Op-Ed in February.

Malley says the entrance of Bolton to the president’s foreign policy team now means the president will be torn between his instincts as a deal-maker and the voice of Bolton, who has staked out his support for military action.

“He’s going to have two voices in his head, so it will be interesting to see which deal prevails,” said Malley.