Unbeknownst to most Americans, President Bush has just spelled out a new strategic doctrine for protecting this country against terrorism. Call it a doctrine of pre-emption.

Its core: The United States must strike at terrorists, or states that sponsor them, “before they hit us.”

The president told West Point graduates on June 1 that Cold War doctrines would no longer suffice. He said containment a 1940s doctrine designed to stop Soviet expansion couldn’t work against “unbalanced dictators with weapons of mass destruction (who) can … secretly provide them to terrorist allies.”

The threat of massive nuclear retaliation, the president added, “means nothing against shadowy terrorist networks. If we wait for threats to fully materialize, we will have waited too long.”

The punch line? “We must take the battle to the enemy, disrupt his plans, and confront the worst threats before they emerge,” the president argued. He called for the military to transform itself into a body “ready to strike at a moment’s notice in any dark corner.” He said Americans must be ready for “pre-emptive action” to defend our lives.

But what exactly does a doctrine of pre-emption mean?

The Washington Post reports that the doctrine won’t be fully articulated until early fall. As debate mounts both in and outside the administration over the new doctrine, there are worrisome hints about what it “might” mean.

It could mean active U.S. military involvement in the overthrow of a host of “evil” regimes suspected of direct or even uncertain terrorist links.

The president, in his State of the Union address, talked of an “axis of evil,” of states that have weapons of mass destruction and might pass them on to terrorists. He named Iraq, Iran and North Korea as three states that are “arming to threaten the peace of the world.”

Some conservative Bush supporters read this as a call for a new version of the Reagan Doctrine. President Reagan expressed support in his 1985 State of the Union for “freedom fighters” everywhere who opposed communism. In Afghanistan, Nicaragua and elsewhere, we gave such rebels military aid and other covert support.

From this precedent, Bush hawks are arguing that the president’s core message is widespread “regime change.” “The Reagan Doctrine primarily aimed at overthrowing communist regimes ended up toppling right-wing dictatorships in the Philippines and South Korea,” wrote editor William Kristol in the March 4 issue of the conservative magazine the Weekly Standard. “So, too, the Bush Doctrine could help undo dictatorships not only in Iraq, Iran and North Korea, but also in, for example, China and Saudi Arabia.”

In the February issue of Commentary, in an article titled “How to Win World War IV,” the neoconservative Norman Podhoretz went even further. He endorsed “some new species of an imperial mission for America, whose purpose would be to oversee the emergence of successor governments in the (Mideast) region more amenable to reform and modernization than the despotisms now in place.” Podhoretz also envisioned “some kind of American protectorate over the oil fields of Saudi Arabia.”

Such grandiose visions of the Bush Doctrine, if they foresee U.S. military interventions to oust a host of odious regimes are fantasies. This is not because the world wouldn’t be better with democratic regimes in the nations on Kristol’s list.

It is because the era of global terrorism is not a carbon copy of the Cold War era. Those countries that make weapons of mass destruction and might one day pass them to terrorists do not fit into one neat category. They can’t be lumped into a communist vs. anti-communist framework. They are not all Muslim, and those that are Muslim are dissimilar.

The means by which the United States must deal with the different problems they pose also are dissimilar. North Korea is vulnerable to economic and diplomatic pressure. Iran’s theocratic regime will ultimately be ousted by its own people. And does anyone really think we’re going to dump rulers in Beijing or Riyadh?

Iraq’s Saddam Hussein may be the one case of a sovereign ruler who must be preempted (many think he is the main target of the new Bush Doctrine). Saddam is dangerous because he lacks any sense of geopolitical limits, has used poison gas, and would be an even greater menace should he obtain nuclear weapons. Moreover, the vast majority of his own people want him gone, and they should be the mainstay of any U.S. effort at overthrow.

Preemption is a doctrine that must be used warily, and the Iraq case can’t serve as the basis for inflammatory theories. Nor should the Bush team get carried away by visions of multiple strikes at terrorists’ hideouts and weapons stockpiles.

As should be obvious from FBI and CIA failures, we don’t have the intelligence capabilities for widespread military pre-emption. Such a strategy should be reserved for exceptional cases. This doesn’t mean that, together with our allies, we shouldn’t work to track and arrest terrorists before they strike.

No one can deny we are in a new era, which demands new strategies to confront stateless terrorists and their sovereign allies. But the times are far messier than the Reagan era. One doctrine of pre-emption will not fit all.

Trudy Rubin is a columnist and editorial-board member for the Philadelphia Inquirer. Her e-mail address is trubin@phillynews.com.