In a possible Trump administration shake-up, Secretary of State Rex Tillerson could be forced out of his position and replaced by CIA Director Mike Pompeo, with hawkish Sen. Tom Cotton of Arkansas taking over as Pompeo's role at the CIA, according to a New York Times report.

Cotton, a former Army Ranger and Harvard law grad, was elected to the Senate in 2014 after serving one term in the House of Representatives. He rose to fame when he penned an unpublished letter to the editor of the Times, accusing three journalists of espionage for their reporting, and calling for them to be jailed. The letter was initially published on a conservative blog and later went viral.

Cotton has also long bucked other politicians on foreign policy and Iran. In 2015, he went behind the back of President Barack Obama and penned another letter, this time to Iran, aimed at unraveling the work the president had done on a nuclear deal with Iran. The open letter, signed by 47 Republicans, warned that “with the stroke of a pen,” the next president could get rid of any deal.

President Donald Trump’s decision to decertify the nuclear deal with Iran this year was heavily influenced by Cotton, according to the Intercept, and went against his own advisers. Cotton compared a nuclear deal with Iran to appeasement of Nazi Germany. He also equated negotiations with Iran to that of killing a person, according to the New Yorker.

“One thing I learned in the Army is that when your opponent is on his knees you drive him to the ground and choke him out,” said Cotton, this year about what dealing with Iran should look like.

“If they’re on their knees in surrender, then you accept their surrender,” he added later.

Along with being tougher on Iran, Cotton has also taken harsher stances on China and North Korea. At the 2016 Republican National Convention, Cotton took aim at Obama's foreign policy.

“[We need] a Commander-in-Chief who speaks of winning wars and not merely ending wars, calls the enemy by its name, and draws red lines carefully, but enforces them ruthlessly,” said Cotton.

Cotton has also taken a hard line on other issues. In a 2015 Armed Services Committee Hearing, Cotton called for more prisoners at Guantanamo Bay.

“In my opinion, the only problem with Guantanamo Bay is that there are too many empty beds and cells there right now. We should be sending more terrorists there for further interrogation to keep this country safe,” said Cotton. “As far I’m concerned, every last one of them can rot in hell. But as long as they don’t do that, they can rot in Guantanamo Bay.”

And despite the U.S. having one of the highest incarceration rates in the world, Cotton advocated for putting more people in prison last year.

"Take a look at the facts. First, the claim that too many criminals are being jailed, that there is over-incarceration, ignores an unfortunate fact: for the vast majority of crimes, a perpetrator is never identified or arrested, let alone prosecuted, convicted, and jailed,” said Cotton in a May 2016 speech. “Law enforcement is able to arrest or identify a likely perpetrator for only 19 percent of property crimes and 47 percent of violent crimes. If anything, we have an under-incarceration problem.”