he most telling moment in Gen. Pervez Musharraf's emotional speech in Islamabad on Wednesday was not when he said that American demands for help in combating terrorism confronted Pakistan with its greatest danger in 30 years. Nor did it occur when he sketched the need for an alliance with the United States and urged, "Trust me!"

The revelatory moment occurred, instead, when Pakistan's military ruler digressed into an anecdote about how the Prophet Muhammad understood 1,300 years ago that there were times that Muslims must make a pact with infidels to survive. Muhammad, the general recalled, even entered into a six-year treaty with the Jewish tribes of Medina in order to concentrate on battles with other non-believers in the region.

"The lesson is that when there is a crisis situation, the path of wisdom is better than the path of emotions," the general asserted. "Therefore, we have to take a strategic decision."

We are now in the fourth iteration of a sorry Pakistan-American relationship built on strategic necessity but constantly poisoned by distrust. A cycle of commitment and abandonment by Washington has sometimes reflected American selfishness and sometimes an American refusal to tolerate Pakistani misbehavior, like its covert nuclear program.

Whatever the cause, it is a record that makes Pakistan wary of President Bush's new embrace. The biggest danger now is that by overstepping in Pakistan — using it as a military base for attacks, for example — the administration could plunge General Musharraf's regime into chaos or even civil war, providing a new opportunity for lethal action by Osama bin Laden and his radical allies. Another risk would be to embolden General Musharraf as a nuclear weapons-toting troublemaker.

The first enlisting of Pakistan as a "front-line state" was in the 1950's, when the Eisenhower administration sought to encircle the Soviet Union with alliances. It was a Pakistani airbase from which Francis Gary Powers took off in 1960 on his ill-fated U-2 spy flight, one of the milestones of the cold war. Yet Pakistan remained mired in poverty and ruled by a succession of military dictators.

In the Nixon years, Pakistan was the crucial link to Henry Kissinger's opening to China. President Richard Nixon ordered a "tilt" to Pakistan in the war with India in 1971. Yet Washington did little to help its "friend," India won the war, and Pakistan was dismembered. Then after the Soviet invasion of Afghanistan at Christmastime in 1979, the United States again rediscovered the value of Pakistan. The Soviets fled a decade later, but Pakistan was left with a legacy of refugees, drugs, guns, crime and religious zealotry that has destroyed its foundation.

Today the situation in Pakistan is extremely fragile, to put it mildly. It is a nation of vast impoverished multitudes, presided over by rival elites — the military, the Islamic clergy, the feudal landlords, the business leaders — all of whom distrust each other. From the nation's independence in 1947, Pakistani leaders have found it no easier to unify their country over Islam than neighboring India has in trying to unify a vast patchwork of religious and ethnic subgroups behind a basically Western idea of secularism.

Failing to create strong governments at home, India and Pakistan have resorted to searching for security by stoking ethnic discord across each other's borders. That is the South Asian way: If you can't be strong at home, at least make trouble for your neighbors. Pakistan has aided the Sikh and Muslim rebellions in India. India helped the Bengalis turn East Pakistan into Bangladesh.

Pakistan has also had its eye on destabilizing Afghanistan, which lies on its western border. Starting in the 1970's, Prime Minister Zulfikar Ali Bhutto aided the mujahedeen guerrillas in their fight against the Communists in Kabul. His daughter Benazir denies it, but her regime is generally believed to have helped their successors, the Taliban, take control in the 1990's.

Now the Pakistanis are being asked to turn against the religious zealots who have been their friends at the request of the infidels in the United States. "Americans need to understand that Pakistanis are not that sympathetic to those bearded guys in Afghanistan," says a Pakistani diplomat. "The question Pakistanis are asking themselves is, `How can we trust the Americans?' "

Vice President Dick Cheney did not help matters when, in his interview with Tim Russert last Sunday, he insensitively referred to Pakistanis several times as "Paks." (Is it conceivable that he would have used a similar slur with the Japanese?) At least the White House spokesman apologized for Mr. Bush's calling the American drive against Osama bin Laden "a crusade."

When I covered Pakistan in the 1980's, I once referred to Pakistani- American "friendship" during an interview with a prominent religious leader and mystic. His stern look stopped me short. "Between a powerful man and a weak man, there can be no friendship," he said. "There can only be a relationship."

Unlike Americans, Pakistanis are looking at this relationship without tears right now. They are asking themselves a simple question: Will the United States accede to Pakistani requests to lift sanctions, overlook their nuclear weapons program, tolerate their military dictatorship or withdraw support from Israel and India? It is hard to imagine Pakistan not ending up feeling betrayed again.