The biggest challenge for the National Security Council isn’t North Korea or Russia. It’s Trump.

Government committees rarely make history, but the National Security Council is an exception to the rule.

The equivalent of a presidential board of directors, complete with its own staff, the NSC makes and oversees national security policy. The scope of its current agenda – from determining the best response to North Korea, to addressing Russia's resurgence – reflects the Council's importance as well as its challenges.

In President Donald Trump's White House, running the NSC falls to Lieutenant General H.R. McMaster, the new national security adviser. A respected soldier-scholar, McMaster has a plate-spinner's job: He must guide a dozen departments and agencies as they bring policy proposals to the NSC; make sure their debates don't devolve into deadlock; and champion those decisions in the Oval Office, all with an eye on the president's diplomatic, economic and defense policy goals.

Reports so far suggest McMaster is trying to put his mark on the Council. He has eliminated two deputy assistant jobs and reportedly wants to reinstall the director of national intelligence and chairman of the Joint Chiefs of Staff to the NSC's nine-member "principals' committee," its senior cabinet-level group. Through an executive order Trump removed both positions from NSC meetings, and replaced them with Steve Bannon, his senior counselor.

But none of these changes solve McMaster's biggest problem – running a disciplined NSC for a president who is anything but. Like previous national security advisors, McMaster must build his personal ties and credibility with the president. But whether he can influence Trump remains to be seen.

From its origins in the Cold War to the policymaking challenges facing the Council today, the NSC's history offers McMaster several lessons worth considering as he shapes his White House role.

The National Security Council inevitably reflects the president and his style.

History suggests that the Trump NSC will be the product of the president it serves.

President Dwight Eisenhower gave his NSC major responsibilities, reflecting his wartime experience as supreme Allied commander well-versed in delegating responsibility and bringing together antagonistic allies to make critical decisions. Eisenhower kept his "principals' committee" small, but expanded the Council.

President John F. Kennedy's Council was different from Ike's. Kennedy shrunk the NSC, preferring a leaner staff that fit his hands-on style. The pendulum swung again with Lyndon Johnson, whose disinterest in foreign affairs and policy details led him to largely ignore the NSC.

Relationships matter.

McMaster needs to staff the NSC with people who know the issues and bureaucratic ropes, but his relationships with the "principals" such as Secretary of State Rex Tillerson and Defense Secretary James Mattis matters even more. Several White Houses demonstrate what happens when these relationships go awry.

Under President Jimmy Carter, National Security Adviser Zbigniew Brzezinski argued for a more assertive policy toward the Soviet Union. His disagreements with Secretary of State Cyrus Vance over relations with Moscow spiraled into public battles, undermining the administration's image at home and abroad.

Despite her rapport with President George W. Bush, Condoleezza Rice fought a different battle; she found herself and her position challenged by Vice President Dick Cheney and Defense Secretary Donald Rumsfeld. A hardliner on terrorism, Cheney clashed with Rice over the treatment of suspected jihadists and other issues after 9/11. In her memoir Rice recounted near-constant friction with Rumsfeld, who pulled no punches after leaving office, dismissing Rice as an "academic."

The national security adviser cannot play second fiddle to the "principals."

McMaster should be at the president's elbow for all national security issues. But because of Trump's preference for management-by-mosh-pit, his family-based inner circle, and his own often erratic behavior, McMaster's role is less certain. His predecessors have been in the same position.

A believer in cabinet government, President Ronald Reagan downgraded the NSC, turning to his principals to make and manage policy. He appointed a revolving door of national security advisers – six in two terms. Virtually all played second string to more powerful figures such as Secretary of State George Schultz and Defense Secretary Caspar Weinberger. Without a strong adviser to handle their differences, however, the men's policy battles – over the Middle East and arms control, among others – paralyzed the administration

Reagan faced the consequences in his second term, when the Iran-Contra scandal revealed his national security policymaking in disarray. Appointed in the aftermath of the scandal to examine the NSC, the Tower Commission criticized the president's relationship with his national security adviser, calling for tighter presidential control over the Council and its cabinet principals.

Even without this level of controversy, McMaster faces major hurdles. Foremost is competition from Trump's inner circle. The Strategic Initiatives Group – a newly established team composed of Trump's son-in-law Jared Kushner and several Bannon acolytes – is encroaching on the NSC's domain. Kushner has also become a liaison to the Oval Office for leaders from more than two dozen countries, challenging McMaster as the point person for foreign access to Trump.

The NSC's principals, McMaster's key policymaking constituency, lack the undersecretaries and assistant secretaries they need. With hundreds of these jobs unfilled the secretaries of State, Defense and Homeland Security, among others, are ill-equipped to handle the issues and decisions that face them when they get to the NSC's table.

To be sure, McMaster could still build an effective council. When Frank Carlucci and Colin Powell became national security advisers after the Iran-Contra scandal, they reshaped President Reagan's NSC, streamlining the Council's decision making. And McMaster has plenty of resources, including an estimated 400-person staff, to get the job done.

But for McMaster to create order out of the chaos that currently defines White House national security policymaking, he needs support from the president. That makes his greatest challenge Trump himself.