As we know, there are known knowns. There are things we know we know. We also know there are known unknowns. That is to say, we know there are some things we do not know. But there are also unknown unknowns, the ones we don’t know we don’t know.

In assessing the national security team that President-elect Barack Obama announced Monday, it seems appropriate to invoke this bit of wisdom that Donald Rumsfeld uttered in February 2002, a little more than 13 months after President George W. Bush appointed him secretary of Defense.

This editorial page praised Mr. Bush’s appointment of Mr. Rumsfeld on Dec. 28, 2000, but the unknown unknowns got us. We knew that Mr. Rumsfeld was a Pentagon reformer, but we didn’t know the United States would be attacked by terrorists nine months later and that Vice President Dick Cheney would become fixated on Iraq and that Secretary of State Colin Powell would help legitimize the tenuous reasons for invading Iraq and that Mr. Rumsfeld would insist on testing his “fewer forces faster” reformist theories there for the next four years.

So let us say this about Mr. Obama’s choices: Based on what we know now, they appear to have the intellect, the political heft and the independence to help the new president navigate what promise to be some very difficult shoals.

Of Mr. Obama’s team, Robert M. Gates, the choice for secretary of Defense, is the closest to being a “known known.” Mr. Gates has been in charge at the Pentagon since the president jettisoned Mr. Rumsfeld after the Republicans’ 2006 congressional election disaster. Mr. Gates had a lot of cleaning up to do, and he did it well.

Along with Mr. Bush, he oversaw Gen. David H. Petraeus’ use of counter-insurgency tactics in Iraq, bolstered by 20,000 additional troops. For many reasons, one of which was those troops, violence diminished. Iraq, however, remains an expensive albatross around the national neck, and Mr. Gates is the right man to help Mr. Obama carefully extricate U.S. forces over the next year and a half.

More significantly, by choosing Mr. Gates, Mr. Obama has cast his lot with the Petraeus-Gates side in the ongoing Pentagon civil war. The two men want to focus Pentagon tactics and spending on small, tactical “brushfire” warfare and less on the Cold War-era strategic warfare favored by some generals, admirals and military contractors. Even with a military budget of $600 billion, you can’t do both.

Also of that school is Gen. James L. Jones Jr., a retired Marine Corps Commandant who will serve Mr. Obama as National Security Adviser. He is an independent-minded warrior-diplomat who will bring a huge measure of gravitas to the West Wing. When you’ve been Supreme Allied Commander-Europe, you learn what’s petty and what’s important.

Indeed, of all the “unknown unknowns” that stretch before the Obama administration, the most intriguing is this: How will Mr. Jones interact with Sen. Hillary Rodham Clinton, D-N.Y., Mr. Obama’s choice as secretary of State?

Consider only that for most of Richard Nixon’s presidency, the most influential voice in foreign affairs was that of Henry A. Kissinger, the national security adviser, not that of William P. Rogers, the secretary of State. How long will Ms. Clinton, who sublimated her ambitions to her husband’s before emerging on her own, be willing to be just a member of the chorus? How well can she keep her husband’s shadow away from the affairs of state? We wish her well; the nation hardly needs another soap opera.

Her intellect and star quality should make her an effective diplomat; she is capable of the long hours and command of excruciating detail that make for effective diplomacy. She can close a deal, and there is no end of deals that need closing.

Say this for Mr. Obama’s team: Among himself, Mr. Gates, Mr. Jones and Ms. Clinton, there will be no shortage of intellectual firepower and ego in the room — and that’s before you stir in Vice President-elect Joe Biden, the former chairman of the Senate Foreign Relations Committee. As a basketball fan, Mr. Obama surely must know that with all-star teams, sometimes there aren’t enough basketballs to go around.