Events in Iraq, Lebanon, and Asia highlight Bush's shortcomings as a leader.

If the world seems to be spinning out of control, that's because it is.

The centrifugal forces were unleashed 15 years ago by the end of the Cold War and the system of international order that went with it. These forces could have been at least somewhat tamed, contained, and redirected by the United States, the one nation that continues to have some degree of global reach in every dimension of power (military, political, economic, and cultural).

The problem is, President George W. Bush and his aides have dropped the ball, have abrogated their responsibilities as stewards of the "sole superpower" (as they like to call themselves), have often behaved as if they have no responsibilities and, worse still, as if there were no centrifugal forces, as if they can jimmy everything into place and under control through sheer willpower and moral righteousness.

Iraq is only the most obvious, and deadliest, case in point. We have 140,000 troops in Iraq. Their only power at this point lies in the leverage that any large foreign-military presence can exert—and the baffling thing is, Bush isn't exerting it. He's not using their potential withdrawal to pressure the Maliki government's policies. He hasn't heeded calls, from observers of all stripes, to engage in diplomacy with Iraq's neighbors or to convene an international conference—if only to get everyone used to talking in a common forum so they can all try to keep the conflagration from spreading across the region, should Iraq implode into anarchy.

So, instead, Maliki, on his own, is reaching out to Iran and Syria. This may be good for his government's security, but it also advances Iran's power and influence. According to a story by Jay Solomon in Friday's Wall Street Journal, the White House has been trying for months to build a coalition of Sunni Arab states to counter Iran's growing influence. John Hillen, assistant secretary of state for politico-military affairs, has visited the six nations of the Gulf Cooperation Council, laying out "an ambitious program to better integrate the U.S. into the GCC's security architecture," including "plans to develop regional maritime security … missile defense … a broader intelligence-sharing mechanism … and … air defenses."

This is a good idea for a lot of reasons, but it also has its limits. First, it's doubtful that many of these governments will back the United States in actions directed explicitly against Iran or, say, Hezbollah. (They started to go along with the Bush administration to some extent this past summer, during the Israeli-Lebanon war, but they backed away when the Israeli attacks spiraled out of control and Bush refused to use his influence to curtail them.)

Second, strengthening the Sunni Arab states, without at least talking with Shiite states, is likely to harden the tensions and widen the fissures. Is this what Bush wants to happen? Does he plan to take part, and actively take sides, in a sectarian, region-wide war? During the middle years of the Cold War, the United States dealt with the Soviet Union and China—sometimes played them off each other—without becoming ally or enemy to either. What's happened to statecraft?

The United States should be mediating this conflict—not just to be an internationalist do-gooder but to promote our interests and to bolster our leverage. Instead, in the wake of Bush's neglect, Iran and Syria are filling the vacuum.

Of course, last week's murder of Pierre Gemayel, Lebanon's most outspokenly anti-Syrian Cabinet member, puts the United States in a bind. Even if Bush were inclined to change course and open a line of dialogue, he can't now, out of a legitimate concern that doing so would send a message that he doesn't care whether Syrian agents assassinate foreign officials. (It's not yet known who killed Gemayel, but Syria must be regarded as a major suspect, given the recent history of such incidents.) On the other hand, if the two countries had already had diplomatic contact, Bush could have used it as leverage now.

Lebanon is another, only slightly less tragic, case in which Bush had vital interests and enormous leverage to advance them—yet did nothing. Lebanon, recall, was the prize exhibit in the freedom march that seemed, for a moment, to be blazing across the planet in the spring of 2005 (it seems like ages ago). Young crowds took to the streets of Beirut, protesting the assassination of Rafik Hariri, the popular former prime minister who had resigned over the illegal extension of the quisling Gen. Émile Lahoud's term as president. They demanded the ouster of Syrian troops—and succeeded.