In my experience there are very few — if any — meetings of the principals committee at which the input of the military and the intelligence community is not vital. With an increasingly belligerent Russia, tensions in the South China Sea and a smoldering Middle East, it makes little sense to minimize the participation of the professionals leading and representing these two groups.

The Trump White House insists that the new organizational structure does not downgrade the roles of the chairman of the Joint Chiefs or the director of national intelligence. (The White House and Gen. Joseph F. Dunford Jr., the current chairman of the Joint Chiefs, have both said that General Dunford will fully participate in the council’s duties.) If this is true, the administration should clarify that by making them permanent members of the principals committee. That would send a strong signal that Mr. Trump will still take seriously the military and intelligence community.

The second much needed adjustment to Mr. Trump’s arrangement of the council is the removal of Mr. Bannon from the principals committee. Putting aside for a moment Mr. Bannon’s troubling public positions, which are worrisome enough, institutionalizing his attendance threatens to politicize national security decision making.

The security council was formed in 1947 to serve a unique role in our government. It facilitates and coordinates, providing a forum through which federal agencies discuss and debate policy and, ultimately, provide counsel to the president about how best to keep the American people safe. At N.S.C. meetings, representatives from the State Department, the Pentagon, the Treasury Department, the intelligence community and other agencies speak freely and critically about the full breadth of options available to the United States. Those discussions can get heated at times. They can certainly get territorial. But they seldom get political — nor should they.