Washington CNN  — 

Richard Grenell, the newly installed acting director of American spy agencies and loyalist to President Donald Trump, began his temporary tenure by moving aggressively to put his stamp on the intelligence community that Trump has repeatedly attacked.

Grenell ousted Andrew Hallman on Friday, a veteran intelligence officer who served as the number two at the Office of the Director of National Intelligence, a source with knowledge of the situation confirmed to CNN. On Thursday, Grenell brought on board a former staffer of Rep. Devin Nunes, a staunch Trump ally and California Republican.

CNN reported earlier this week that Hallman was leaving. The New York Times first reported Grenell ousted him.

There are fears within the intelligence community that Hallman may not be the only top official forced out. Career intelligence professionals worry that Shelby Pierson, the person in charge of evaluating intelligence regarding election security with the ODNI, will also be fired, according to a former top intelligence official.

Pierson is still on the job, according to sources with knowledge of her status. She did not reply to a request for comment on Saturday.

Grenell also asked to see the intelligence behind the classified briefing last week where lawmakers were told Russia was interfering in the 2020 election to aid Trump, the Times reported.

Present and past colleagues, as well as diplomats who have tussled with him, describe Grenell as an aggressive, intelligent and caustic operator who loves to pick a fight, air the drama on Twitter and make sure everyone in the room knows his loyalty lies first and foremost with the President.

‘An honest dealer’

Trump’s discovery that intelligence officials had briefed the bipartisan group of lawmakers on Russia’s efforts led him to angrily jettison acting Director of National Intelligence Joseph Maguire on Wednesday and install Grenell in his place.

Donald Trump Jr. suggested to CNN on Thursday that Grenell’s commitment to the President was a factor in his selection and said he looks forward to having “an honest dealer” leading the intelligence community.

“All I want is honesty in these places. Whether it’s the Justice Department, whether it’s there, I just want people who aren’t partisan hacks,” Trump Jr said, adding that he believes Grenell, the US ambassador to Germany, will be the same kind of disruptive force within the intelligence community that he has been diplomatically.

Given Trump’s troubled relationship with the intelligence community, which he has publicly denigrated and undermined, numerous former administration officials said they are concerned that Grenell was appointed to “clean house” and purge the government of those deemed to be leakers or whistleblowers.

A spokeswoman for Sen. Jeff Merkley, an Oregon Democrat, said in a Thursday statement that Grenell “has also been dismissive of the threat of Russia’s meddling in the US, a fact that is doubly concerning as Germany is one of our closest and most important allies in pushing back on Russian aggression on the world stage.”

The Office of the Director of National intelligence did not respond to a request for comment.

News that Trump has appointed Grenell to oversee US intelligence shook Washington, triggering questions about how the Republican operative with no intelligence experience will perform, even as he remains the top diplomatic envoy to Berlin. Foreign diplomats and US observers who have watched Grenell on the world stage say his past performance provides an answer.

Trump Jr. said Friday that Grenell had been “the most effective person we’ve seen in an ambassadorial spot in decades.”

That assessment isn’t widely shared. Foreign envoys, German diplomats and US analysts note that Grenell, who is supposed to be America’s main eyes and ears on the ground, is so distrusted that Berlin’s government and business officials are wary of meeting him.

Grenell’s debut was so tumultuous, Chancellor Angela Merkel raised it with Vice President Mike Pence, telling him the new ambassador’s style required some “getting used to,” one person with knowledge of the exchange said. This person added that Merkel has never warmed to Grenell.

“Diplomats are supposed to be diplomatic,” the German official said. “That’s not his specialty.”

‘Attack dog’

A former co-worker described Grenell as smart and polished – and as an “attack dog” who has made it his mission to serve Trump over country. A former State Department official said Grenell’s style has made him “kryptonite” in Berlin.

“He has spent his time in Germany auditioning for a bigger role in the Trump administration rather than trying to develop effective leverage over German foreign policy,” this official said. The State Department has not confirmed that Grenell will maintain his post as ambassador to Germany, even though US officials have said that is the case.

Grenell responded to a request for comment on the criticism by sharing an analysis piece from The Jerusalem Post on his time in Germany.

At the United Nations, where Grenell served from 2001 to 2008 as the US spokesman, diplomats will heave a sigh of relief that this promotion won’t bring him back there, said Richard Gowan, UN director at the International Crisis Group.

“A lot of UN officials worried that Grenell might return to New York to head [the US mission to the UN] at some point and will be delighted that he’s bound for Washington instead,” Gowan said. “He is still remembered around the UN as a pretty pugnacious operator.”

The 53-year-old Michigan native’s take-no-prisoners style, his friendship with Trump Jr. and his ties to the President have made him a force to be reckoned with. He’s not likely to change. “The President wants a disruptor, he’s getting a disruptor,” a former administration official said in describing Grenell, one of the US’ few ambassadors who identify as gay.

A second former administration official called Grenell’s appointment “a troubling development” given the ambassador’s lack of intelligence experience and his track record.

“He tended to freelance on policy matters and he strayed from many of the directives he got from Washington,” this former official said.

Grenell was out of step with the State Department on his effort to push countries to decriminalize homosexuality. Because he worked on the initiative with Ivanka Trump and had approval from the President, he could pursue the effort without full buy-in from Secretary of State Mike Pompeo, the former official said.

Grenell’s disregard for protocol has created friction with Pompeo, according to other sources, one of whom said there’s “no love lost” between the two.

‘That’s all that matters’

The first former official added that Pompeo has long been irritated by Grenell’s tendency to circumvent the proper channels on TV appearances and his propensity for getting involved in issues outside of Germany.

The second former administration official explained why Grenell managed to get away with this: “The President likes him, and in his day and age, that’s all that matters.”

Trump has long viewed Grenell’s remit as going well beyond Germany and given him wide leeway in his duties. The President has frequently praised Grenell’s television appearances and tweets, telling one adviser Grenell is his “favorite ambassador.”

Jeff Rathke of the American Institute for Contemporary German Studies at the Johns Hopkins University said Grenell’s style makes him “one of the most unconventional ambassadors that the Trump administration has sent abroad.”

“He has generated a lot of publicity and he has clearly been able to use a direct connection to the President to raise issues in the German-American relationship or issues more broadly,” Rathke said, pointing to Grenell’s advocacy on LGBTQ issues, warnings to countries about using China’s Huawei 5G and his focus on the Nord Stream 2 pipeline.

How Grenell’s approach translates to the more discreet world of intelligence remains to be seen. His appointment is expected to last only a matter of months, sources familiar with the situation said, with one pinpointing a tenure of 90 days.

The former Fox news commentator was sworn in as ambassador in May 2018 despite dissenting votes from senators who pointed to his derogatory tweets about women and his “toxic political discourse.”

Grenell started with a bang. In his first day on the job, he sparked outrage by calling for German businesses in Iran to “wind down operations immediately.”

In June 2018, the newly minted ambassador crossed a diplomatic red line in an interview with Breitbart News by commenting on internal politics, saying one of his key goals was to “empower” conservatives to take power across Europe.

His comments “infuriated” officials in Berlin and in capitals across Europe, according to one European diplomat, with many repeating calls for his resignation.

Yet with Trump’s skepticism toward Europe, in particular Germany, Grenell has ingratiated himself by echoing the President’s tough views, often with an added edge.

The former State Department official said that approach hasn’t made him an effective US envoy.

‘Caustic rhetoric’

“Because of his caustic rhetoric and his tendency to make arguments public, Grenell has basically been frozen out of access to the senior levels of the German government,” this former official said. “There are many ministers who will not meet with him.”

The official pointed to the fallout after German automaker Volkswagen met with Grenell and he subsequently claimed the company was going to stop exporting to Iran. “They were angry that he tried to do a victory dance after a private discussion,” the official said.

Now “people are reluctant to meet him because they fear he may publicize parts of their discussion, and in general they do not want to feel like they are rewarding his diplomatic behavior,” the former official said. “That goes for political leaders and big German companies.”

Experiences like Volkswagen’s coupled with Grenell’s twitchy Twitter trigger finger “have reduced him in Germany to a figure who acts on social media and with a few sympathetic journalists but who, for the most part, is … not really influencing what is happening in how Germany sets its policies and implements.”

‘Suspicion’

Grenell’s dual-hatted role as spy chief and ambassador to Berlin is not going to make him any more effective, said Brett Bruen, a former foreign service officer who’s the president of Global Situation Room, a consulting firm.

Bruen pointed to the history of distrust in Germany for US spy agencies after leaks by Edward Snowden revealed the US National Security Agency was tapping Merkel’s cell phone.

“There is an incredibly high level of suspicion, distrust of anything that speaks of intelligence,” Bruen said. “People will look past Grenell’s bravado and boastfulness as long as he is wearing a civilian uniform, but now, donning the spy gear and trying to convey a message about why Germany should support us on Iran or Russia or the spread of extremism is just a nonstarter.”

“Who in Germany is going to want to hang out with America’s chief spy?” Bruen asked.

CNN’s Jeremy Diamond, Jim Acosta, Kevin Liptak, Alex Marquardt and Zachary Cohen contributed to this report.