This year a new conservative movement, led by William Kristol’s Project for the New American Century, formed around a single idea: support for a new, proud American imperialism. The debate on whether America is an imperial power is over, P.N.A.C.’s scholars insist; the American empire is real. The challenge now is to figure out what to do with it.

”We had better get used to seeing ourselves as others see us,” says Tom Donnelly, P.N.A.C.’s deputy executive director. ”It doesn’t matter if we don’t consider ourselves an empire. Others see us as impinging on their lives, their space, their way of life. If we are going to protect our enduring interests, in the Middle East and elsewhere, then we have to do something about it.”

So far, that something mostly boils down to spending more — a lot more — on the military. P.N.A.C. has deluged the Bush administration and Congress with articles and press releases calling for vast increases in the defense budget, and expressing suspicion about Secretary of Defense Donald Rumsfeld’s ideas on ”reforming the military.” They claim that military spending fell to less than 3.5 percent of the nation’s gross domestic product during the Clinton years, ”back to pre-World War II levels.” The new imperialists would like it to return to its cold war average of 10 percent of G.D.P., increasing the defense budget by at least $75 billion to $100 billion per year.

”We’d better understand the full range of tasks we want our military to do, from Balkans-like constabulary missions to no-fly zones to maintaining enough big-war capacity,” Donnelly contends. The P.N.A.C. wants it all — a military that can confront China over Taiwan, throw up a missile defense, remove Saddam Hussein from power, fight two conventional wars at the same time and effectively hunt down terrorists, drug lords and guerrillas.

Donnelly refers longingly to the strategies and tactics of the old British Empire, back when it was policing the Raj and maintaining the Pax Britannica. But the American empire is different, he says, in that it holds no territorial ambitions.

”The fundamental difference between America and other, past empires is that we don’t issue writs in Washington that we expect others to follow,” Donnelly says. Rather, our new manifest destiny is to disseminate our values. ”We have seen the spread of liberty in our own country as our power spreads, as well as around the world,” he says. ”As we have grown more powerful, we have extended rights to women, to racial minorities, to everyone.” These are the values — along with free-market capitalism — that the American empire should stand for, the new imperialists maintain.

In Afghanistan, Donnelly speaks of ”economic development” and long-term diplomatic engagement aimed at ”not just winning the war, but creating a stable peace.” He rejects talk of an ”easy-exit strategy” and demands that we commit American troops to a peace-keeping force and take the lead in building ”some sort of state structure in Afghanistan.”

Historically, America’s most ambitious imperialist projects have been undertaken during some of the more progressive periods in American history. Conservatives have generally been more skeptical of attempts to impress American values upon foreign nations. So it’s no surprise that the debate over imperialism has exposed deep fissures in the national conservative movement. Donnelly’s most intractable opposition comes from other conservatives — including much of the administration’s foreign policy establishment. Bush’s foreign policy, after all — at least prior to Sept. 11 — has been based upon a partial global disengagement; a self-interested, ”realistic” unilateralism. P.N.A.C.’s analysts criticize the ”almost contemptuous rejection” with which the administration has backed out of international agreements.

Kristol sees domestic political advantage in the imperial strategy; in an essay, he and Robert Kagan promise that the new imperialism will make the Republican Party ”once again the party of Reagan — a party that stands for that ‘distinctly American internationalism’ that we believe a majority of Americans embrace.”