But whether a smaller O'Brien-run NSC will have more influence on the president is anything but clear. Trump has long chosen his gut feeling about policy advice. And NSC officials fear that the impeachment trial, which is about whether Trump is trying to pressure Ukraine to identify a political rival, is making the president's confidence in the US bureaucracy even lower than before.
Several NSC officials have already given a scathing testimony to the House committees, and the whistleblower, who first reported on the President's phone call to Ukrainian employee Volodymyr Zelensky, was said to have been a CIA employee who had previously served NSC staff had been reported. President Trump compared the whistleblower and the officials who talked to him to spies.
For the time being, O'Brien, who assumed the post of repressed conservative hawk John Bolton in September, appears confident in his approach.
"We rationalize the National Security Council," he told CBS News "Face the Nation" on Sunday. "We do not have to rebuild the Department of Defense, the State Department, and the Department of Homeland Security in the White House. We have great diplomats and soldiers and ̵
POLITICO spoke with several current and former Trump administrators as well as with outside experts to learn the changes. Most asked for anonymity because of the sensitivity of the subject, although O'Brien himself was quite open about his plans.
The NSC is to act as the organ that coordinates US national security and foreign policy throughout the executive. Depending on the administration, the influence is different.
Trump administration officials say the goal is to reduce the NSC's political staff to fewer than 120 by January. According to O'Brien, the number drops to 174. The number does not include the technical and support staff of the institution, for which many cuts are unlikely.
O'Brien has stated that he wants to seek a leadership similar to that of the NSC during the first term of then President George W. Bush. These numbers continued to grow – and often accurate figures are not disclosed – to the point where there were more than 200 political slots under President Barack Obama.
The Obama team has shrunk the body a bit in the last few years, and Trump continued that.
Much of O'Brien's shrinkage will be due to signs of wear and tear: most NSC policy workers are hired by other agencies or departments such as the Pentagon for a year or two, as a rule. When the details are done, fewer can count on extensions. Her roles remain vacant.
The NSC sections, which are expected to lose the most slots, are the so-called "functional directorates". The functional directorates deal with geographically unrelated issues such as human rights or the fight against terrorism.
At least two functional directorates – strategic planning and emerging technologies – are being phased out, current and former NSC staff said. The Directorate for International Economics, which previously reported to both the NSC and the National Economic Council, now only reports to the NEC.
A government official said the Strategic Planning Department had already done its main job of preparing Trump's National Security Strategy. The person in charge of this direction, Kevin Harrington, has been appointed strategic advisor to O'Brien, and has been mandated to "make a net assessment of all our strategies to determine how effective our strategies are," the official said.
New technologies that theoretically deal with issues such as artificial intelligence were considered below-average and twice as good as other parts of government.
The change in the International Business Directorate is partly about clarifying who is responsible for what, said current and former NSC staff. There were complaints that the members of this team, if they had a dual reporting structure, played one or the other role in discussions between the agencies, depending on what benefited them.
O'Brien also has no plans to revive the Homeland Security Council, which essentially exists only on paper after he was originally a principal under Trump.
The counterparts to the function directorates are the regional directorates dealing with, for example, Europe, the Middle East or South Asia.