Washington ? Fifty-six years ago American officials worried about unconventional uses of weapons of mass destruction. In a 1946 congressional hearing, J. Robert Oppenheimer acknowledged that a few people could smuggle components of an atomic bomb into New York City. Asked how such components could be detected in a crate or suitcase, he answered: “With a screwdriver.”

President Bush would rather rely on regime change than screwdrivers to protect America. So he is unsheathing a doctrine “anticipatory self-defense” via pre-emptive war that might become a dangerous sword in other hands. But as a reminder of the alternatives, say “screwdriver.”

Saddam Hussein’s regime, founded on fear leavened by cupidity, will soon learn the value of those as substitutes for popular consent in infusing people with a willingness to die. During preparation for Desert Storm, an Israeli official, after being briefed by Gen. Norman Schwarzkopf on the war plans, said: Too many hospital beds, too few prisoner-of-war pens. He was right: Iraq’s army was overrated.

Because of economic sanctions, among other things, Iraq’s military is less formidable today. America’s military is much more formidable than it was 11 years ago because it incorporates new technologies as avidly as Gen. Pershing did in 1917 when (as William R. Hawkins notes in Parameters, the quarterly journal of the U.S. Army War College) high tech meant radios, trucks and biplanes.

Still, Americans should not assume use of large-scale military power against Iraq will be as easy as three recent uses were. Desert Storm was a 100-hour land war following a 38-day air campaign. U.S. objectives were achieved in Serbia from an altitude of 15,000 feet. Afghanistan may seem to have confirmed Gen. Billy Mitchell’s 1925 book “Winged Defense”: “It is probable that future wars again will be conducted by a special class, the air force, as it was by the armored knights in the Middle Ages.”

Whether easy or difficult, regime change in Iraq will not be the first such post-Sept. 11 exercise. Afghanistan was. And Saudi Arabia’s regime may be changed by reverberations from action against Iraq, particularly if that action is seen to be the prelude to democratization.

The House of Saud almost certainly is a dead regime walking. Saudi Arabia’s male unemployment rate is 30 percent. Its population growth birth control is disapproved is among the most rapid in the world (3 percent per year). Eric Rouleau, a French diplomat, writing in Foreign Affairs (“Trouble in the Kingdom”), says that since the overthrow of the Taliban, Saudi Arabia is the Islamic world’s most rigorous theocracy: “Universities require male professors teaching women’s classes to give their lectures through a closed-circuit one-way television system … 30 to 40 percent of the course hours in schools are devoted to studying scripture.” Furthermore, the marriage rate is sharply dropping:

“Unable to afford the traditional dowry, many young Saudi men are now doomed to a prolonged celibacy. At the same time, growing numbers of young women are refusing to marry men chosen for them by their families, men whom their would-be brides are not allowed to meet before their wedding night. As a result, an estimated two-thirds of Saudi women now between 16 and 30 years of age cannot, or will not, marry.”

Sooner or later, and probably sooner, all this will meet its match in modernity. America’s reluctant semi-allies in Europe should support American actions that hasten that day. Demography is, if not destiny, at least a shaper of nations’ fates, and Francis Fukuyama of the Johns Hopkins School of Advanced International Studies notes demographic trends that give Europe a huge stake in the transformation of the Middle East.

Barring a surge of immigration into Europe, which the political climate there precludes, by 2050 the median age in Europe will be approaching 60. But in the Middle East, North Africa and sub-Saharan Africa, the median age will be about 21 which, Fukuyama notes, is what has been normal through most of history. “So you’re going to have this little island of well-to-do elderly people surrounded by vast numbers of people who are a good deal younger and poorer, all wanting to move to the island.”

If Iraq’s next government derives its powers from the consent of the governed, the entire region may be changed. “Brazil,” according to a familiar jest, “is the country of the future and always will be.” Many people too pessimistically believe that the Arab world is next on the list of regions to experience democratization and always will be.

George Will is a columnist for Washington Post Writers Group.