Defense Secretary James Mattis is keenly aware of John Bolton's rapid ascension within the White House and is making a concerted effort to make nice with President Donald Trump's new national security adviser amid a shifting power dynamic at the highest levels of the administration.
Mattis invited Bolton to the Pentagon for breakfast on Wednesday as part of his push to establish a cooperative working relationship that mirrors the dynamic he once had with former Secretary of State Rex Tillerson, in which the two men often met privately and worked out their positions before presenting a unified position to the President, two defense officials told CNN.
Chief Pentagon spokesperson Dana White told reporters that Wednesday's breakfast was likely the beginning of a regular series of meetings that could eventually include newly confirmed Secretary of State Mike Pompeo.
Prior to Tillerson's ouster, he, Mattis and Pompeo would typically meet for breakfast or lunch once a week to informally discuss major national security issues facing the administration.
One of Trump's most trusted advisers, Mattis has clearly wielded significant influence since joining the administration, but he lost a particularly consistent ally when Tillerson was unceremoniously fired last month.
Like Mattis, Tillerson argued against leaving the Iran nuclear deal and consistently stressed the importance of prioritizing a diplomatic resolution to tensions with North Korea, a source close to the White House previously told CNN.
But while Mattis has been able to navigate the complex political minefield within an unpredictable Trump administration in a way that avoids drawing the President's ire, sources close to the White House have told CNN that the same could not be said for Tillerson, whose firing was due in part to the fact it had become clear he was not on the same page as Trump and wanted to handle foreign policy his own way.
The addition of Bolton and Pompeo represents a dramatic overhaul atop the administration's national security team that many argue leaves Mattis more isolated than ever, as both men were selected due to their strong personal relationships with the President and on the premise that they fundamentally align with Trump's own way of thinking.
And while Mattis hopes to reconstruct the dynamic he had with Tillerson by informally meeting with Bolton and Pompeo on a regular basis, early indications are it is unlikely that they will defer to the Defense secretary in the same way Tillerson once did -- setting the stage for a potential clash over key issues like North Korea and Iran.
One source close to the White House told CNN that going forward, any potential conflict is likely to stem from the fact that the power dynamic is no longer heavily weighted in Mattis' favor, and situations will likely arise in which he will be forced to "share the porch" with other strong personalities whose views may conflict with his own.
Several defense and administration officials also told CNN that Trump appears frustrated with the narrative that he has to rely on generals for advice.
However, the President does understand Mattis is a popular figure and that it would be difficult to find an acceptable reason to replace him, the officials said.
The Pentagon has stressed that Mattis believes he and Bolton can collaborate effectively.
"John Bolton is an American. And he can work with him," White said this week when asked about Mattis' relationship with the new national security adviser.
Primed for conflict?
While the two men met for the first time in the days following Trump's decision to hire Bolton, a source close to the White House previously told CNN that Mattis opposed naming him to replace ousted national security adviser H.R. McMaster and pushed for other candidates he viewed as more malleable to his own views.
Mattis has done his best to downplay notions that he is concerned about working with Bolton -- previously saying that he looked forward to working with the former UN ambassador and that he hoped the two men held "different world views" to avoid "group think."
During their first interaction at the Pentagon last month Mattis even joked about speculation of a possible conflict, telling Bolton that he had heard that he was "actually the devil incarnate."
But despite Mattis' public optimism, he is aware of the fact that Bolton has wasted no time flexing his new-found authority in the West Wing -- internal posturing that has created waves among some senior administration officials, a source told CNN.
Multiple sources with knowledge of the hierarchy have told CNN that Bolton has been given wide leeway to hire who he likes and dismiss those he doesn't -- often bypassing chief of staff John Kelly and reporting directly to Trump.
Several top officials at the National Security Council have already resigned under pressure, been fired or decided to leave during Bolton's short tenure at the White House. But it was Bolton's decision to push out homeland security adviser Tom Bossert -- much to the surprise of Kelly -- that sent ripples through the administration.
According to a source close to the White House, Kelly was fuming after he learned of Bossert's firing and told Bolton to run any future staffing moves through the appropriate channels for approval.
But despite Kelly's warning, Bolton went on to fire two other NSC officials -- Ricky Waddell and Nadia Schadlow -- without looping in the chief of staff -- making it clear that he answers directly to Trump, the source said.
Part of Bolton's animosity toward Kelly stems from Kelly's opposition to hiring Bolton as national security adviser, the source added -- a conflict that could fuel possible resentment toward Mattis in the future.
The White House has cited Bolton's desire -- and right -- to build his own team but the decision to tap Mira Ricardel as his new deputy also sets the stage for potential tension with Mattis.
A well-known Republican hawk who worked on the Trump transition team, Ricardel clashed with Mattis following the election, several sources told CNN.
At the time, Ricardel pressed for a number of individuals to be nominated to key Defense Department positions, but Mattis rejected them in favor of personnel he preferred, sources said.
Early signs of tension
Early indications that tension may be brewing between Mattis and Bolton were on display earlier this month as Trump mulled options for a retaliatory strike against the Syrian government in response to a suspected chemical weapons attack outside of Damascus.
After days of deliberations, Trump ultimately announced that the US had carried out the muscular strike that he had demanded and said that he was "prepared to sustain" a coordinated campaign of strikes on Syrian targets "until the Syrian regime stops its use of prohibited chemical agents."
But what actually transpired in Syria seemed closer to the careful strategy advocated by Mattis and his military brass.
During a meeting with top military officials prior to the strikes, Trump grew upset at the options being presented, according to people familiar with the conversations. He insisted he wanted to go further than the limited strikes he ordered last year, which did little to prevent the Assad regime from allegedly attacking civilians again with deadly chemicals.
Trump's views were bolstered by Bolton and US envoy to the United Nations Nikki Haley, who argued that any action should go beyond the limited set of strikes Trump ordered from Mar-a-Lago last April, a senior administration official said.
A source close to the White House told CNN that tensions were high between Mattis and Bolton during the weeklong discussions over the best course of action.
Like Trump, Bolton advocated for stronger military response while Mattis pushed back and ultimately won the argument with the approach that was agreed upon.
However, another source with knowledge of the discussions downplayed reports that the disagreement was an indication of a larger rift between the newly minted national security adviser and Defense Secretary -- adding that while deliberations did pit Mattis against Bolton, the conflict was largely seen as the process working the way it should.
The Pentagon said that Trump expects Mattis and Bolton to bring a range of options to the table -- even if they disagree with one another over the best course of action.
"What I see is a very comprehensive review of decisions. ... The President brings together people from different perspectives, and he challenges them," White told reporters at the Pentagon this week.
"This department provides options ... but at the end of the day, it's the President of the United States that decides," White added.