But Americans were once admired in the Middle East. In the beginning, after the fall of the Ottoman Empire, America was seen in the Middle East as a rising force less interested in empire than the Europeans. There were Arabs, encouraged by Woodrow Wilson’s self-determination rhetoric, who thought, if they were to be denied independence, an American mandate would be preferable to either a British or a French one. But secret deals between the two colonial powers sealed their fate, and America was not interested, then, in Middle Eastern entanglements.

After World War II there was another flash of hope in the Arab world that Franklin Roosevelt would liberate them from colonial rule, but it was not to be. My first experience with the red-hot emotions of the Egyptian street came in 1956 when demonstrators’ rage, pouring across the bridges of the Nile, was directed against the British. When Britain and France, in cahoots with Israel, invaded Egypt that year to take back the Suez Canal from Egyptian control, President Eisenhower said no, and they promptly withdrew their armies. Americans were popular in Cairo then.

But America has changed in the last half century. As British and French power began to falter in the Middle East and Asia, America decided first to prop them up and then to take their place. Along the way stability began to trump any lingering Wilsonian and Rooseveltian anti-colonial ideals as the best way to combat first Communism, and now Islamic extremism.

One can look at the last half century as one long American effort to fill the vacuum left by retreating French and British influence. It is no coincidence that America’s wars of the last 50 years — Vietnam, the Persian Gulf, Iraq, and even Afghanistan — have been in what were once British and French colonies or protectorates.

The United States courted Egypt after British influence waned, and eventually succeeded in wooing it away from the Soviets. But this meant dealing with military men, for all Egypt’s leaders since King Farouk was sent packing in 1952 have been military men.

Anwar Sadat, beloved in the West for making peace with Israel, was less popular in his native land. When he was assassinated by religious extremists Hosni Mubarak seemed the perfect, steady, and calming personality to maintain Egypt’s stability. For a long time he was, and we forget now that he fought a long and desperate campaign against Islamic militants and won.

Mubarak always made it clear that the peace with Israel would be maintained, and although it’s been a cold peace, it has endured to this day. As a result Egypt has become a major recipient of US foreign aid.

President Obama is now reviewing that aid, and it would be grotesque to throw such an old and faithful ally to the wolves. But despite the pattern of the last 50 years, America likes to be seen on the side of freedom and democracy, and does not want to be tarred with supporting tyranny.

America has to live in the world as it is, not as America would want it to be. There was a brief, neo-conservative moment in George W. Bush’s first term, in which it was thought by the “Vulcans,’’ as his team called themselves, that America had the power to insist that the world become what America wanted. That illusion soon faded.

America loves democracy until elections produce what America doesn’t want, and then it doesn’t love democracy, as in the case of Hamas in Gaza. And revolutions have a way of turning out badly, with hope and freedom turning to terror and dictatorship, as in 18th century France, and 20th century Russia and Iran.

In the present crisis, as in the past with the shah of Iran and President Marcos in the Philippines, it is difficult to know just when political triage is necessary to stay on the right side of history —when it is necessary to withdraw life support systems to let one Egypt die so another can be born.

**H.D.S. Greenway’s column appears regularly in the Globe.