Mr. Bolton has come to the opposite conclusion.
He not only fervently advocated the attack on Saddam Hussein from his post at the State Department during the Bush administration, but he also defended its aftermath, and has said he remains convinced it was the right decision. Over the past three years, Mr. Bolton has advocated bombing Iran, attacking North Korea, and carving a new state out of Iraq and Syria.
Mike Pompeo, the nominee for secretary of state, said at the Aspen Security Conference in July that the most dangerous thing about North Korea was the fact that its young, moody and reportedly ruthless leader, Kim Jong-un, controls its weapons.
“So from the administration’s perspective, the most important thing we can do is separate those two. Right?” said Mr. Pompeo, who at the time was months into his current job as C.I.A. director. “Separate capacity and someone who might well have intent, and break those two apart.”
Assuming that Mr. Pompeo is confirmed, he and Mr. Bolton, the two most forceful, aggressive new members of the policy team, will have to decide in what order they can risk those confrontations. The Trump administration has said it is open to direct talks with Mr. Kim by May — the same month by which the president has said he will scrap the Iran nuclear accord.
“Even if you are going to be a superhawk, you can’t do all these at once,” said Rolf Mowatt-Larssen, a former C.I.A. station chief in Moscow who later hunted down Pakistani nuclear technology as the Energy Department’s chief intelligence officer. “And if you want to go to war with Iran and North Korea, you have to expect to alienate your allies and run headlong into the Russians.”
William J. Burns, a longtime American diplomat who was Mr. Bush’s ambassador to Russia and Mr. Obama’s deputy secretary of state, predicted that if the new team exits the Iran deal and confronts North Korea, the first beneficiary is likely to be President Vladimir V. Putin of Russia.
“He looks for splits,” Mr. Burns said of Mr. Putin. “He knows he will benefit if we walk away from the Iran deal, because it will put a wedge between us and our European allies.”