Ho Chi Minh’s post-World War II appeals for assistance to another American president — Harry S. Truman — again went unanswered; and Ho, who had worked with American intelligence agents during the war, was ostracized as a dangerous Communist. But many people in Asia saw that it was only a matter of time before the Vietnamese ended foreign domination of their country.

For the world had entered a new “revolutionary age,” as the American critic Irving Howe wrote in 1954, in which the intense longing for change among millions of politicized people in Asia was the dominant force. “Whoever gains control of them,” Howe warned, “whether in legitimate or distorted forms, will triumph.” This mass longing for political transformation was repressed longer by cold war despotism in the Arab world; it has now exploded, profoundly damaging America’s ability to dictate events there.

Given its long history of complicity with dictators in the region, from the shah of Iran to Saddam Hussein and Hosni Mubarak, the United States faces a huge deficit of trust. The belief that this deep-seated suspicion can be overcome by a few soothing presidential speeches betrays only more condescending ignorance of the so-called Arab mind, which until recently was believed to be receptive only to brute force.

It is not just extremist Salafis who think Americans always have malevolent intentions: the Egyptian anti-Islamist demonstrators who pelted Hillary Rodham Clinton’s motorcade in Alexandria with rotten eggs in July were convinced that America was making shady deals with the Muslim Brotherhood. And few people in the Muslim world have missed the Israeli prime minister’s blatant manipulation of American politics for the sake of a pre-emptive assault on Iran.

There is little doubt that years of disorder lie ahead in the Middle East as different factions try to gain control. The murder of Ambassador J. Christopher Stevens in Libya, the one American success story of the Arab Spring, is an early sign of the chaos to come; it also points to the unpredictable consequences likely to follow any Western intervention in Syria — or Iran.

As in Southeast Asia in 1975, the limits of both American firepower and diplomacy have been exposed. Financial leverage, or baksheesh, can work only up to a point with leaders struggling to control the bewilderingly diverse and ferocious energies unleashed by the Arab Spring.

Although it’s politically unpalatable to mention it during an election campaign, the case for a strategic American retreat from the Middle East and Afghanistan has rarely been more compelling. It’s especially strong as growing energy independence reduces America’s burden for policing the region, and its supposed ally, Israel, shows alarming signs of turning into a loose cannon.