Cohen-Watnick’s removal comes after the revelation by The Atlantic on Wednesday [2017] of the dismissal of Rich Higgins, another Iran hawk who was the NSC’s director of strategic planning. Higgins was sacked for circulating a memo in which he alleged that there was “a Maoist” insurgency within and without the government of “globalists and Islamists.”

“The removals come as McMaster [termination April 2018] seeks to consolidate his control of security policy and remove loyalists to Michael Flynn, Trump’s first national security adviser…”

"McMaster had previously tried to remove Cohen-Watnick from the National Security Council but was overruled by Trump…"

https://www.jta.org/2017/08/02/news-opinion/politics/mcmaster-pushes-cohen-watnick-iran-hard-liner-out-at-national-security-council