the national security adviser and delineates whether certain issues will be handled in the White House or at the agency level, extending even to who will chair certain meetings.

The answers to those questions have been both decisive and divisive in the past. President George W. Bush vetoed a play by his vice president, Richard B. Cheney, to chair the “principals’ meetings” of top officials in the president’s absence, insisting that they be led by his first-term national security adviser, Condoleezza Rice.

Obama, in his first national security directive, centralized decision-making in the White House, directing that third-tier policy committees across national security agencies be chaired by an NSC official, rather than giving a designated department the lead role.

[How the Obama White House runs foreign policy]

Clinton set up the NationalEconomic Council (NEC) because, “in a different era, he wanted to give economics more importance in foreign policy,” said James Mann of the School of Advanced International Studies at Johns Hopkins University. Mann has written several books on national security organization.

While Obama folded the Bush-created Homeland Security Council (HSC) into the NSC, his first counterterrorism adviser, current CIA Director John Brennan, was given broad leeway and access to the president.

So far, Trump has created a structure that, depending on one’s perspective, seems designed for either diffused authority or conflict. In addition to the NSC, to be headed by retired Lt. Gen. Michael T. Flynn, he has revived the HSC, retained the NEC and created a new National Trade Council — all of whose leaders apparently will report directly