A former aide to John Bolton says "deep in his heart," the national security adviser "believes the president is a moron.”

The harsh critique appears in an expansive profile of Bolton published by the New Yorker on Monday, which also included an unnamed Western diplomat saying Bolton "had to cut his balls off" and offer them to President Trump to get the job as head of the National Security Council.

The unlikely coupling between Trump and Bolton became official in April 2018 when the latter became national security adviser, replacing H.R. McMaster, whom Trump had blamed for blocking him from doing what he wanted.

The piece features comments from Mark Groombridge, who worked with Bolton for 15 years and was his adviser on Asian affairs while Bolton served as U.S. ambassador to the United Nations under President George W. Bush. He questioned how someone like Bolton can stand working for Trump.

“John is thinking, 'To the extent I can modify or mollify the President’s actions, I will,'” Groombridge said. “He is truly a patriot. But I wonder how he goes into work every day, because deep in his heart he believes the president is a moron.”

Bolton, who was an early supporter of the Iraq War in 2003, has clashed with Trump due to their dissenting views on military intervention in places such as North Korea.

“The trouble for Bolton is, Trump does not want war. He does not want to launch military operations,” a Western diplomat who knows Bolton said. This person also detailed the hoops Bolton was forced to jump through in order to get a top position in the administration, including an effort to be considered for the secretary of state before Trump picked oil CEO Rex Tillerson.

Bolton replaced former McMaster as national security adviser in April 2018. “To get the job, Bolton had to cut his balls off and put them on Trump’s desk,” the diplomat said.