Mike Pompeo is a hard-line Republican, a former businessman turned politician and President Donald Trump's pick to replace Rex Tillerson as secretary of State.
"I think Mike Pompeo will be a truly great secretary of State, I have total confidence in him," Trump told reporters before departing the White House on Tuesday.
Noting Pompeo's "tremendous energy" and "tremendous intellect," Trump said their relationship has been very good and they are "always on the same wavelength."
After Trump's comments, State Department spokesman Steve Goldstein said Secretary Rex Tillerson hadn't planned to leave the post before news of the firing came down. What's more, Tillerson "did not speak to the president this morning and is unaware of the reason" for his firing, the spokesman added. Goldstein himself was later fired for contradicting the administration's account of Tillerson's termination.
And while it is unclear what Tillerson's exit means for other top Cabinet officials, Secretary of Defense James Mattis has undoubtedly lost an ally.
Mattis, a former Marine commander with a military career spanning four decades, forged a close relationship with the former Exxon Mobil CEO largely due to their diplomatic approach to national security matters.
"We talk two, three times a day, sometimes. We settle all of our issues between he and I, and then we walk together into the White House meetings. That way, State and Defense are together," Mattis said in January.
Tillerson and Mattis, along with Treasury Secretary Steven Mnuchin, reportedly had a so-called suicide pact in which the others would resign if Trump tried to remove one of them.
As CIA director, Pompeo delivered Trump's intelligence briefing nearly every day and has said that the president "asks really hard questions."
Pompeo, 54, became CIA director more than a year ago after serving in the House, where he was a member of the House Intelligence Committee.
Below is a roundup of Pompeo's views on various national security matters:
While the ongoing investigation continues to determine the extent of Russian meddling in the 2016 U.S. presidential election, Pompeo has downplayed the Kremlin's interference.
Speaking at the Washington-based think tank Foundation for Defense of Democracies last year, Pompeo said that the intelligence community determined that Russia's interference ended up not impacting the outcome of the election.
However, the intelligence assessment report on this very topic said the community "did not make an assessment of the impact that Russian activities had on the outcome of the 2016 election."
And so, Pompeo's comments at FDD were not only a direct contradiction to the report but also in line with Trump's views.
The staff shakeup installs an ardent critic of the Iran nuclear deal as the nation's top diplomat and narrows the difference of opinion between the White House and the State Department, analysts say.
Similar to Trump, Pompeo has called the nuclear agreement "disastrous."
In January, Trump said he would stick with the deal for now, but wants to fix the agreement's "terrible flaws."
Meanwhile, Pompeo has said that Tehran is "intent on destroying America" and that he was looking forward to "rolling back" the deal. This is why it looks like Pompeo's new assignment is bad news for Iran.
Tillerson's firing also removes another member of the administration's internationalist wing and emboldens Trump to take more punitive measures against rivals, including Iran and Venezuela, they warn.
While serving as a congressman from Kansas, Pompeo criticized the attempt by President Barack Obama to close down the prison at Guantanamo Bay, Cuba.
"GTMO has been a goldmine of intelligence about radical Islamic terrorism. I have traveled to GTMO and have seen the honorable and professional behavior of the American men and women in uniform, who serve at the detention facility," Pompeo said in 2016.
Pompeo was also against any prisoner transfers from Guantanamo saying, "The detainees at GTMO are treated exceptionally well, so well that some have even declined to be resettled, instead choosing to stay at GTMO."
He added: "It is delusional to think that any plan the president puts before Congress to relocate radical Islamic terrorists to the U.S, and potentially Fort Leavenworth Kansas, will make our country safer. The reality is that this proposal will ultimately put Kansans and Americans in danger."
It remains to be seen if Pompeo agrees with Trump's push for harsh interrogation techniques such as waterboarding. Trump's pick to succeed Pompeo at the CIA, Deputy Director Gina Haspel, is known for her role in the agency's "black site" prison program, in which terrorism suspects were detained and tortured.
As a lawmaker, Pompeo was a long-standing supporter of restoring the National Security Agency's sweeping attempts to collect Americans' communications data.
And in a 2016 op-ed published in The Wall Street Journal, Pompeo furthered his viewpoint by laying out a plan to expand U.S. surveillance capabilities.
"Congress should pass a law re-establishing collection of all metadata, and combine it with publicly available financial and lifestyle information into a comprehensive, searchable database," he wrote.
In an interview with C-SPAN in 2016, Pompeo said that NSA whistleblower Edward Snowden should be brought back from Russia and given due process in the United States.
"I think the proper outcome would be that he would be given a death sentence for having put friends of mine, friends of yours, who serve in the military today at enormous risk because of the information he stole and then released to foreign powers."
— CNBC's Tom DiChristopher contributed to this report.