For friends and enemies abroad who have been wondering who's really in charge of U.S. foreign policy, the answer is now unmistakable: A victorious and newly confident George W. Bush is running the show. That has benefits for a nation at war that needs clear leadership. But it has dangers that can be summed up in the Greek word for leaders who, through overconfidence, destroy themselves: hubris.

What's been happening in Washington in the past week has been something between a sensible shake-up and a partisan purge. Which way the reorganization ultimately tilts will depend on the president. He gets to decide whether he wants to emulate Harry Truman in properly enforcing discipline among his senior aides, or Richard Nixon in circling the wagons and rooting out "enemies."

Much as Washington and the world admired Colin Powell, it's hard to fault Bush's decision to replace him. For all his gifts, Powell simply wasn't effective in framing or implementing policy for this administration. After his quasi-dissent on Iraq -- privately warning the president but publicly delivering the rationale for war at the United Nations -- he lost credibility on both the left and the right. The man who once kept a note on his desk at the Pentagon that said "Never let them see you sweat" lived by that rule, to a fault. Mr. Cool may be a more effective dissenting voice on the outside.

Condoleezza Rice's appointment also makes sense, if you assume that the real leader of the foreign policy team will be the president. Bush trusts Rice absolutely; she's his kind of intellectual -- smart but not introspective. That was a liability when Rice was national security adviser; then, her job was to challenge the president and tee up issues for timely White House decisions.

Instead, she saw her role as channeling the boss -- being decisive when he'd made up his mind, tolerating disorder when he hadn't. "Condi decided her job was to figure out where the president was, and then support that, rather than challenge him," says one man who knows Bush and Rice well. Personally, I hope in the new job Rice encourages more foreign policy realism from the president and less of his moralism.

Rice had two big problems as national security adviser, named Rumsfeld and Cheney. The secretary of defense basically refused to play the National Security Council game. He reserved the right to overrule any decision made by Pentagon subordinates in lower-level interagency meetings, which meant that nothing was ever decided until it got to the principals. And sometimes it wasn't decided at all, as has been the case with Iran policy. The NSC has been working on a draft Iran policy document since early 2002.

As for the vice president, he undercut Rice by operating through his office what sometimes seemed to be a second NSC staff. Foreign diplomats complained that trying to understand the Bush administration was like reading the Kremlin in the old days of the Soviet Union. For better or worse, that problem has disappeared.

The real danger for the administration lies in the fiasco at the CIA. Certainly the agency needs change, but what we are watching is a classic Washington tale of arrogant congressional staffers run amok. The CIA's new director, Porter Goss, is a likable enough fellow. But as a former Republican member of Congress, he was a bad choice for an agency that needs to be outside politics. Unfortunately, Goss compounded the problem by bringing along several aides who confused their own personal and political agenda with the nation's security.

Goss's chief of staff, Patrick Murray, had been a divisive figure when he held that job on the House intelligence committee. I'm told he blocked the kind of bipartisan staff work the committee had adopted in the past and began picking fights with the agency. Long before Goss went to the CIA, Murray was feuding with senior officers of the clandestine service. Last week, Murray demanded that the operations chief fire his deputy. He refused and both men are now out.

Goss sent out an e-mail this week to the CIA that was probably meant to be reassuring, but made things worse. He told bruised agency employees that he wanted to "clarify beyond doubt the rules of the road," to wit: "We support the administration and its policies in our work." It was the wrong message, and illustrative of a wider paranoia on the right about the CIA that really is Nixonian.

Goss can probably repair the damage, but only if he disciplines his self-important aides. The bureaucratic warriors should be reminded that the country is in a real war, and good operations officers are precious. The self-styled president's men, who've never recruited an agent but think they know how to run the CIA, should check their arrogance at the door. If loyalty to the president becomes the defining principle of foreign policy, the president himself will suffer.