Sen. Rand Paul of Kentucky issued a warning shot to President-elect Donald Trump on Tuesday, urging him not to select John Bolton as his secretary of state.

Trump is rumored to be considering the official from George W. Bush’s administration for the position; he is also reportedly considering Rudy Giuliani, the former New York mayor. Bolton is a prominent proponent of the Iraq War.

Paul slammed Bolton in an op-ed article published by Rare, calling him a “menace” who “never learned and never will.”

“Bolton is a longtime member of the failed Washington elite that Trump vowed to oppose, hell-bent on repeating virtually every foreign policy mistake the US has made in the last 15 years – particularly those Trump promised to avoid as president,” Paul wrote.

He continued:

"All nuance is lost on the man. The fact that Russia has had a base in Syria for 50 years doesn't deter Bolton from calling for all out, no holds barred war in Syria. Bolton criticized the current administration for offering only a tepid war. For Bolton, only a hot-blooded war to create democracy across the globe is demanded."

Paul noted that Bolton was a vocal proponent of the Iraq War and as recently as last year publicly maintained his support for the US invasion.

"I still think the decision to overthrow Saddam was correct," Bolton told the Washington Examiner in May 2015.

In his op-ed article, Paul praised Trump for opposing the Iraq War "early" - though there is no evidence Trump did so before the war started - and argued that Bolton's appointment to the position would ensure Trump's campaign promises to change "our disastrous foreign policy" would be broken.