The only job with less security than “NSA for Trump” is “drummer for Spinal Tap.”

Actual quote from reporter Eli Lake: “[I]n recent weeks, Trump has privately expressed regret for choosing McMaster.” There’s a nonzero chance that we’ll be on our third national security advisor before Trump has spent four months in office.

Trump was livid, according to three White House officials, after reading in the Wall Street Journal that McMaster had called his South Korean counterpart to assure him that the president’s threat to make that country pay for a new missile defense system was not official policy. These officials say Trump screamed at McMaster on a phone call, accusing him of undercutting efforts to get South Korea to pay its fair share.

This was not an isolated incident. Trump has complained in front of McMaster in intelligence briefings about “the general undermining my policy,” according to two White House officials. The president has given McMaster less face time. McMaster’s requests to brief the president before some press interviews have been declined. Over the weekend, McMaster did not accompany Trump to meet with Australia’s prime minister; the outgoing deputy national security adviser, K.T. McFarland, attended instead…

Bannon and Trump, according to White House officials, pressed McMaster to fire a list of Obama holdovers at the National Security Council who were suspected of leaking to the press. The list of names was compiled by Derek Harvey, a former Defense Intelligence Agency colonel who was initially hired by Flynn. McMaster balked. He refused to fire anyone on the list and asserted that he had the authority to fire and hire National Security Council staff. He also argued that many of these appointees would be ending their rotation at the White House soon enough.

There’s more, some of which is already known to the public and some of which isn’t. Among the known friction points is McMaster begging Trump to no avail not to use the phrase “radical Islamic terrorism” in his address to Congress in February and being blocked by Steve Bannon and Jared Kushner when he tried to remove Ezra Cohen-Watnick from the NSC after Cohen-Watnick was accused of helping Devin Nunes to access old intel reports in which Trump officials were “unmasked.” Supposedly McMaster has also taken to “lecturing” Trump during briefings instead of letting him ask questions. And the Bannonites in the White House are worried that McMaster is “trying to trick the president into the kind of nation building that Trump campaigned against,” whatever that means. It may refer to another alarming story filed by Eli Lake last month alleging that McMaster was eyeing a build-up of “tens of thousands” of U.S. troops in the Euphrates River Valley to lead a multinational force against ISIS in Iraq and Syria. Are there any senior White House officials who lost a power struggle with McMaster not long ago who might be eager to whisper to the media that he’s fallen out of favor with the president?

Note the bit in the excerpt about Derek Harvey being a Flynn hire. Cohen-Watnick was also brought on by Flynn. So was McFarland, who’s on her way out but still enjoys enough cachet with Trump to have joined him on that Australia trip. McMaster appears to be stuck trying to manage an NSC stocked with other people’s loyalists — Flynn’s, Obama’s, Bannon’s, but maybe not so many aligned with McMaster himself. It seems like more than pure chance that today’s Lake scoop happens to coincide with Sally Yates’s testimony about Mike Flynn and the leaks from Obama alums claiming that Trump was warned about Flynn in advance. It’s as if the Flynn loyalists inside the White House want to remind the world that the new guy has plenty of problems of his own. And then of course there’s the (alleged) petty indignities to deal with, like this:

Rumor has it McMaster also was upstaged by Kushner in front of reporters last Friday as the Trump son-in-law pulled "rank" on the general.

— David Rothkopf (@djrothkopf) May 8, 2017

It’s impossible to know how much of Lake’s story is truth versus spin from anti-McMaster sources, but it makes me wonder if McMaster would have offered his resignation already if he was a civilian instead of an active-duty officer. Exit question: McMaster shouldn’t undermine his boss by reassuring South Korea that getting them to pay for THAAD isn’t U.S. policy, but why does Trump seem so intent on creating friction with South Korea at a moment as fraught as the current one with the North — not just over THAAD but over lesser matters? McMaster may be guilty of excessive zealousness in trying to hold a key alliance together but you can understand why he’s worried.