This weekend, President Trump issued his National Security Presidential Memorandum (NSPM) 2—a document outlining how he intends to organize and use his National Security Council (and Homeland Security Council) to develop, coordinate, and implement national-security policy. It makes significant changes, reshuffling the permanent membership of its most senior and influential committees. But the real concern about the NSC, one week into a new administration, is less the specific shape it takes, than whether the president will incorporate it into his decision-making process at all.
With every new president comes a new memorandum or directive (and acronym) organizing and guiding the NSC. President Obama issued Presidential Policy Directive-1 (PPD-1); President George W. Bush issued National Security Presidential Directive-1 (NSPD-1); President Clinton issued Presidential Decision Directive-2 (PDD-2); and President George H.W. Bush issued National Security Directive-1 (NSD-1). It is important to state up front that NSPM-2 ultimately serves as the operating manual of the NSC but it is not necessarily how national-security decision-making will ultimately happen in practice.
National Security Councils have been organized and have functioned differently under every modern American president since Harry Truman. They generally reflect the decision-making preferences and worldview of the president. I am not a historian of the NSC, but I have had the privilege of serving on the NSC staff for two presidents (George W. Bush and Barack Obama) and four national security advisers. And based on that experience, some aspects of how Trump plans to organize his national-security decision-making process seem particularly significant.