WHO COULD REPLACE BOLTON?

Charles M. Kupperman, the acting adviser: Kupperman, a former Reagan administration official and defense contracting executive, is a longtime Bolton associate. Known by many national security officials by his nickname, “Kupperware,” for his blandness, Kupperman, 68, was appointed in January as deputy national security adviser under Bolton. Shortly after Bolton left the White House on Tuesday, Hogan Gidley, a deputy White House spokesman, told reporters that Kupperman would serve as Bolton’s acting successor. Acting officials have a way of sticking around in this administration for indefinite lengths of time, but Kupperman’s track record as someone ensconced in Bolton’s inner circle could shorten his tenure. Stephen E. Biegun, the representative to North Korea: Biegun, the United States’ special representative for North Korea, had a firsthand window into the clashes between Bolton, who never wavered from a hawkish, hard-line stance on North Korea, and the president, who has tried to use a charm offensive to persuade Kim Jong Un, the North Korean leader, down a path to denuclearization.

Brian Hook, the administration’s Iran representative: Hook, 51, is also said to be in contention to succeed Bolton. He is the administration’s special representative for Iran and a senior adviser to Pompeo. Hook, a lawyer brought into the State Department under Rex Tillerson, is one of the remaining survivors from that era. An administration official familiar with Hook’s relationship with Trump said that the two “interact on Iran” and that “the president is happy with how the strategy is going there.”

Douglas Macgregor, another Fox News fixture: Trump is almost certainly familiar with Macgregor, a retired Army colonel who has written several books on reorganizing the military. But more important to Trump, he also appears frequently on one of the president’s favorite Fox programs, Tucker Carlson Tonight. In June, when Trump decided at the last minute to call off a round of strikes against Iran, he had listened to Tucker’s assertion that a strike could prove politically fatal. A frequent guest on the show that week was Macgregor, who backed up that rationale.

Richard Grenell, U.S. ambassador to Germany: Grenell is personally liked by the president. At times, he has emulated Trump’s brash diplomatic style. Shortly after beginning his post in Germany, he elicited the annoyance of politicians there by admonishing any German companies doing business with Iran. Grenell, 52, who is gay, is perhaps best known for enthusiastically defending the president’s position on gay rights, even as the Trump administration has taken steps to roll back civil rights for gay and transgender people. He has also led an effort to decriminalize homosexuality around the globe. Lt. Gen. H.R. McMaster, Trump’s former adviser: McMaster, who was ousted last year weeks after a furious tweetstorm from Trump over his comment that there was “incontrovertible” evidence of Russian election interference, has received at least one phone call from the president on matters of national security, according to a report from NBC News and confirmed by the New York Times. The chances he is offered the job? “Less than zero,” according to a person familiar with his historically fraught relationship with Trump. In any other administration, that would mean he wouldn’t have a chance.