McMaster had purged Derek Harvey, one of the NSC’s best people on the Middle East, for trying to fire Obama holdovers.

“In the late 1980s, Harvey traveled throughout Iraq by taxicab—500 miles, village to village—interviewing locals, sleeping on mud floors with a shower curtain for a door. He [was] full of questions, intensely curious and entirely nonthreatening. After the 1991 Gulf War, when the CIA was predicting the inevitable fall of Iraqi dictator Saddam Hussein, Harvey, then a major, insisted that Hussein would survive because members of the Sunni community knew their fortunes were tied to his. He was right. Months before the 9/11 terrorist attacks, Harvey wrote an intelligence paper declaring that al Qaeda and the Taliban leadership in Afghanistan posed a strategic threat to the United States.”

And why was Harvey fired?

That dispute was followed by a bigger one. Bannon and Trump, according to White House officials, pressed McMaster to fire a list of Obama holdovers at the National Security Council who were suspected of leaking to the press. The list of names was compiled by Derek Harvey, a former Defense Intelligence Agency colonel who was initially hired by Flynn. McMaster balked. He refused to fire anyone on the list and asserted that he had the authority to fire and hire National Security Council staff.

And McMaster keeps using that authority to purge patriots from the NSC.

More here.