(TNND) — President Donald Trump’s national security team shake-up might not have a big impact on the administration’s foreign policy.

Mike Waltz is out as Trump’s national security adviser.

Secretary of State Marco Rubio will at least temporarily fill that role while maintaining his current responsibilities, which also include serving as the acting administrator of the U.S. Agency for International Development and the acting archivist at the National Archives.

Waltz, meanwhile, will be Trump’s pick to replace Rep. Elise Stefanik as his nominee for United Nations ambassador.

“Yeah, it's a massive demotion,” Oklahoma State University politics professor Seth McKee said of Waltz’s move from national security adviser to potential U.N. ambassador.

“I'm surprised he agreed to do it,” McKee added.

McKee said this could be some kind of damage control over the Signal group chat incident.

“But I think there's something else behind this,” he said.

And McKee said he didn’t expect the shake-up to change the trajectory of Trump’s foreign policy.

“The people who keep the ear of Trump and stay in his orbit are the ones who bend to him, and certainly Rubio's a great example of that,” McKee said. “Maybe Waltz didn't bend enough. Maybe he was giving him advice that was too hawkish, that was too sort of traditional Republican foreign policy.”

Gordon Gray, a former ambassador who now teaches at the Elliott School of International Affairs at George Washington University, also said he’s not expecting definitive policy impacts from this shake-up to play out in Ukraine, the Middle East and elsewhere.

“(Waltz’s) firing shows that there are, first of all, there's no strategic coherence vis-à-vis foreign policy in this administration,” said Gray, who was ambassador to Tunisia from 2009 until 2012 and had 35 years of government service. “And second of all, there's a very significant divide between people like Mike Waltz, who was known to be very tough on Iran, on Russia and on China. But his views, I think, were at odds with a more neo-isolationist perspective of many in Trump's orbit.”

McKee described Trump’s approach to foreign policy as “transactional.”

Gray’s colleague at GW, Peter Loge, the director of the School of Media and Public Affairs, previously offered a similar description of Trump’s approach. Loge said Trump can sometimes be mischaracterized as an isolationist.

“Trump views relationships transactionally, and his foreign policy is based on transactions,” Loge told The National News Desk in March. “What do we get? What do we have to give up? And if we get more than we give up, then that's a win."

The Trump administration calls its foreign policy approach “America First.”

What led to the shake-up?

Gray also mentioned the Signal chat incident as a factor in Waltz’s ouster as national security adviser.

But, he said, “I don't believe that in and of itself was the reason.”

Signal is an encrypted but commercially available messaging app.

And Waltz, Rubio and other high-level administration officials were discussing what Gray described as “highly classified operational information” via the app when the chat was inadvertently shared with journalist Jeffrey Goldberg of The Atlantic.

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Waltz took responsibility for the lapse, but he also denied knowing Goldberg.

Waltz slammed Goldberg’s character and told Fox News that Goldberg somehow got “sucked into this group” that was discussing military strikes on Houthi militants in Yemen.

Gray said Waltz “looked like he was fumbling” in his defense of the incident.

And Gray said Trump likely wasn’t happy that Waltz may have had Goldberg in his contact list.

But both McKee and Gray said differences in philosophy within the Trump administration might’ve played just as important of a role as the concerns over the Signal gaffe.

Waltz is quite hawkish in his foreign policy approach, both men said.

“And what we also know is that Rubio sincerely is hawkish. But he wants to be president, and so he's very malleable,” McKee said.

McKee said Trump and those around the president, might have grown to see Waltz as being less than fully “America First.”

Gray said Rubio has earned the trust of Trump, convincing the president that he’s completely on board with the administration’s agenda despite Rubio’s hawkish, traditionally Republican foreign policy track record.

“There's about a 179-degree difference between Sen. Rubio's views on foreign policy and Secretary Rubio's views on foreign policy,” Gray said.

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McKee said it’s tough to say how long Rubio can keep up both roles as secretary of state and national security adviser.

Both jobs are vitally important and too much for one person to do alone, he said.

“It doesn't make sense to try to stretch him like this,” McKee said. “I mean, no matter your thoughts on politics, just bureaucratically speaking, this needs to end sooner than later.”

Henry Kissinger was the only other person to hold both positions. That was 50 years ago.