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John Bolton, who has advocated strikes against Iran and North Korea, is Trump’s new national security advisor.

We’ve known for months that H.R. McMaster, who replaced Michael Flynn as Trump’s national security advisor in February of last year, was not long for this administration. He and the president simply didn’t get along, and by the fall of 2017 McMaster had even lost the support of his closest allies in the cabinet, Defense Secretary Jim Mattis and (now former) Secretary of State Rex Tillerson. The last straw may have been a public fight about whether Russia interfered in the 2016 election, but it’s possible that the author of a book about how important it is for advisers to tell the president hard truths never had a chance.

McMaster’s replacement will be Bolton, the mustachioed cable news fixture. Bolton has been particularly vocal about the need for military action against both Iran and North Korea, suggesting that the nuclear agreement the U.S. signed with the former and the upcoming talks with the latter may be doomed.

Previously, Bolton had been accused of manipulating intelligence during the lead-up to the Iraq War when he worked in George W. Bush’s State Department. Bolton later served for two years as the Bush administration’s ambassador to the United Nations. A neoconservative who believes the U.S. is being infiltrated by Islamists, Bolton can be expected to ratchet up tensions around the globe—and to create disturbances with allies and with members of both parties in Congress.

Bolton’s appointment is the culmination of Trump’s cabinet shakeup. The Trump Cabinet 1.0 was filled with compromise picks aimed at winning over the Republican establishment. The second cabinet is filled with loyalists and extremist hawks.