President Trump's national security adviser has drawn the wrath of Trump's populist supporters, friendly media outlets and allies of chief strategist Steve Bannon as the dynamics of the West Wing once again shift amid a staffing shake-up that shows no signs of slowing down.

Tensions between Bannon and H.R. McMaster, who took the reins of the National Security Council in February, bubbled over late last week after McMaster dismissed a top NSC aide who was widely viewed as an advocate for the president's campaign promises. Amid the subsequent backlash from Trump's nexus of populist supporters, the president issued a rare statement of support for McMaster.

Internal rivalries have ebbed and flowed throughout Trump's young presidency with little lasting effect on the White House hierarchy until recently. The White House's roster of top staffers remained stable through months of intrigue until the recent departures of press secretary Sean Spicer and outgoing chief of staff Reince Priebus.

For example, Bannon and Priebus sparred in the early weeks of the administration before developing a close alliance, and Bannon feuded with Trump's son-in-law and senior adviser Jared Kushner before the two reached a detente in April at the president's request.

But the increasingly public rift between Bannon and McMaster does not stem from disagreements over access to Trump or battles for influence in the West Wing, sources familiar with the situation say. Bannon and McMaster have clashed for purely ideological reasons, a fact that could make their conflict more intractable and prolonged than the infighting that preceded it.

A source close to the White House told the Washington Examiner the removal of Ezra Cohen Watnick, senior intelligence director on the NSC, "never would have happened under Reince" and said Trump did not sign off on the move because he had already given incoming chief of staff John Kelly broad permission to oversee hiring and firing decisions below the senior counselor level.

Multiple sources said Trump was not informed in advance of Cohen Watnick's termination, which Kushner previously resisted when McMaster raised the possibility weeks earlier.

The source said Cohen Watnick's removal was a "red line for a lot of people."

Two other NSC aides have also left recently, stoking speculation that McMaster has begun to purge his team of members loyal to his predecessor, former national security adviser Mike Flynn, and to Bannon. Derek Harvey, a top Syria adviser and Iran hawk, was let go from the NSC before Kelly arrived at the White House, and strategic planning director Rich Higgins was also ousted before Trump replaced his chief of staff.

Although conservative Trump loyalists insist McMaster orchestrated the firings in order to rid the NSC of Bannon allies, a senior administration official told the Washington Examiner the three terminations were "unconnected" and each decision was made based on "inappropriate" actions taken by the aides in question.

In one case, the official said, McMaster was not even aware a member of his team had been asked to leave and was informed of the move only after that person was fired.

McMaster and Bannon represent two very different factions of Republican foreign policy orthodoxy. Bannon, the former head of Breitbart News, is an advocate of reduced global engagement and aggressive action against Iran, the Islamic State, and "globalist" economic policy.

McMaster, on the other hand, is said to support more conventional foreign policy ideas, including the maintenance of the status quo when it comes to the Iran nuclear deal.

A source familiar with the situation told the Washington Examiner McMaster's push to recertify the Iran agreement ruffled feathers inside and outside the White House and even sowed doubt about his fitness for the position with Trump. The source said McMaster expressed doubt during a recent conference call that Iran had even violated the terms of the Iran deal, a position that would undercut Trump's assertion that the agreement was poorly negotiated and has failed to rein in a belligerent Tehran.

Trump promised during the presidential campaign to tear up the Iran nuclear deal immediately upon taking office, although at other points he suggested he would simply be stricter in enforcing the pact's terms.

The source familiar with the talks said tensions between McMaster and the conservatives surrounding Trump have simmered for months, but noted Kelly's arrival has empowered McMaster to make moves that were previously prohibited.

"I think there's been animosity to him for a long time, but his hands were tied until Kelly came in," the source said.

Another person close to the White House said Trump has been informally presented with at least three positions to which McMaster could be reassigned if the situation with his national security adviser became truly untenable, including the possibility of placing McMaster in charge of the war in Afghanistan.

White House aides have spent months debating how to approach the U.S. involvement in Afghanistan, with Bannon pushing for the administration to scale back its military footprint and McMaster advocating for a surge in military resources. Trump publicly delegated decision-making power about Afghanistan troop levels to Defense Secretary James Mattis, but the larger regional strategy is still a subject of discussion.

McMaster's allies have dismissed the recent uproar over his personnel decisions as the latest whim of the alt-right, which has targeted several other White House aides deemed insufficiently loyal to the president's platform.

The sudden push to oust McMaster among populists such as Mike Cernovich, a pro-Trump reporter, and Roger Stone, a former Trump adviser who is believed to remain close to the president privately, has been characterized by the NSC head's supporters as a manufactured effort to divide the White House staff. McMaster's supporters believe the effort is aided in part by Russian Twitter bots that spread a hashtag calling on Trump to "#FireMcMaster" over the weekend.

But one source close to the White House said this characterization of the opposition to McMaster is misleading, although he conceded the national security adviser may not have personally devised the plan to blame criticism of his job performance on the alt-right.

"McMaster clearly has an organized campaign to keep his job, and these people are spreading this idea that it's the alt-right and the Russians, and that is outrageous," he said. "So many people are repeating this alt-right Russia meme ... this didn't just come of out of nowhere."

Trump could find removing his second national security adviser a difficult task should his relationship with McMaster -- who, according to multiple sources, has flaunted his explosive temper in meetings -- deteriorate even further.

The president has already asked for the resignation of his first national security adviser over Flynn's lies to the vice president, has dismissed his FBI director, created the conditions for his press secretary to resign by hiring a highly controversial communications director who he subsequently ousted, replaced his chief of staff with his Homeland Security secretary, and presided over the ousters of several lower-level aides, from deputy chief of staff Katie Walsh to the latest removals at NSC.

Creating a high-profile vacancy in the West Wing at such a volatile time could prove challenging for Trump, who gave Kelly the discretion to fire or keep McMaster when he tapped the former Department of Homeland Security chief late last month.

One source said he expected Trump to "bide his time" with McMaster at NSC to avoid feeding the perception of White House chaos, regardless of how dissatisfied with his national security adviser he may become.