It is just about 30 years since the wall around Iran went up. And it is a few days away from fully 20 years since the Berlin Wall came down.

The Berliner Mauer had been up for more than a quarter century, and its surface facing east, grim gray, was a metaphor for life in the German Democratic Republic. On its western face graffiti evoked the freer spirit of the half-city whose heart had nonetheless been broken by the Soviet goose step that divided it. And the Cold War was won on the very day the authorities of the D.D.R. were simply coerced by the power of human will to let its subjects scramble over the deeply ugly barrier into a Berlin with life and life-blood.

There are three broad reasons that the Wall came down. The first is that the communist system itself was a Potemkin Village, and even the village facade spread from the Union of Soviet Socialist Republics--always distrust political projects pompously named!--all the way through eastern Europe was not pretty. Neither was it efficient. It's human relations were, well, inhumane. No, they were cruel, although the Bolshoi Ballet danced serenely. My friend Dr. Jerry Groopman, the great chronicler of contemporary medicine, returned from a trip to Moscow a few years before the fall. And his report after visiting a few hospitals: "There is an ongoing epidemic of tuberculosis. The Soviet Union is a failure." This was not an oversimplification.

The second reason for the collapse of both the Warsaw Pact and the U.S.S.R. was the problem of nations and nationalities. The Pact put the Soviets as sovereign over great historic peoples. This simply could not last. There is just so much humiliation that Poles and Hungarians, Czechs and Rumanians could take. Moreover, the Soviet Union was also a union of coerced ethnic groups with pasts of which they were both conscious and proud. The regime began to aggress against these already shortly after the revolution, and these aggressive strategies soon included starvation, exile, population transfer and the importation of Russian nationals into the lands of others. Not many observers or, for that matter, scholars noticed--let alone, saw deeply--these issues abuilding. I was lucky. The greatest historian of communism, at least in the languages I read, Adam Ulam (now deceased), who was the supervisor of my doctoral dissertation at Harvard, saw these phenomena plenty clear and thus was always optimistic about the Soviet collapse. Look at some of his books and a few of his TNR pieces to get a sense of his depth and breadth. Also on the national question, see Hélène Carrère d'Encausse's masterful The End of the Soviet Empire: The Triumph of the Nations, a volume the publication of which in English by New Republic Books (in collaboration with Basic Books) I had much to do. 

The third reason for the fall of the endlessly aggressive Soviet Union was the fidelity of American presidents, the Congress and the people to the material (also, if necessary, military) and spiritual struggle against communism. There are some presidential exceptions, to be sure. Jimmy Carter, for instance, hadn't a clue. He was just plain dumbfounded by Moscow's invasion of Afghanistan. And he, like Barack Obama, felt he could contain the Tehran ayatollahs, poor man. In any case, he had already proclaimed at a Notre Dame commencement in 1977 that "we are free of that inordinate fear of communism..."

But before that there was Dwight Eisenhower whose foreign policy half-brain was John Foster Dulles, a pompous and righteous man who embodied the essence of an old saying: "I'd rather face 10,000 fanatics on horseback than one Presbyterian who is convinced he's right." I've already written about the pair's betrayal at Suez of France, Britain and Israel in a stupidly forlorn attempt to entice Gamal Abdel Nasser into the Western camp. Nasser's name can still evoke passion among Arabs in the Middle East. After all, like Arafat, he was the father of many failures, permanent failures, I would say. But why prejudge history?

This desertion by Ike and his patrician counselor is not what I have in mind now. I was 17 and at Brandeis University when the people of Budapest took to its streets. My memory of these days is not rich. But I do recall waking up to my usual 6:30 a.m. radio program alarm. As always, it was the gravelly voice of Bernard Cardinal Cushing, not yet known as J.F.K.'s bishop, reciting the Rosary: "Hail Mary, full of grace, the Lord is with thee..." Soon enough there was news and the voice of someone I'd never heard or heard of. Her plea was "help us." She, it turned out, was a veteran socialist (and not, as Herbert Marcuse tried to persuade us, one of many C.I.A. agents). The revolutionary government she served lasted barely ten days.

But these were ten days that shook the world. And it was not so much Soviet tanks that put them to an end, but Eisenhower's and Dulles' cool indifference to the first sign of decay in the communist world. Maybe they thought they already were on the side of history in Egypt. So why bother?

I think back to October-November 1956 and, of course, I also think of Suez and how the president and his secretary of state had cooly betrayed our allies. And now this same pair were about to betray the very people whom our radio broadcasts had actually summoned into the streets and alleyways of Budapest. There was really nothing to be done at home. But we tried to do something. 

What little I did was to join in founding a group called the Greater New England Collegiate Committee for a Free Hungary. At its head was the already very eminent Yale art historian Vincent Scully. We convened at Boston's Fanueil Hall where Sam Adams and the Sons of Liberty had gathered to stake their claims against Britain. The hall was full. I remember we raised some money, alas, for refugees ... to Austria where Kurt Waldheim (whom only some of you remember) kept them from entering. The crowd was sombre, realizing that no aid to the revolution in Hungary would come from the United States.

Still, three decades later the satrapies of Moscow would begin to crumble one by one ... and then the communist center itself.

Can you imagine the fall of the ayatollahs? I can, and so can learned Abbas Milani, professor of Iranian studies at Stanford, whose writings you can read here, with an additional important article in both the print and on-line New Republic next week.

But can President Obama imagine an Iran freed from the iron grip of the mullahs' madness? There is nothing in his behavior to suggest that he can or, for that matter, that he would be pleased if he could. His first visit to a Muslim country was for two days in Turkey in April. He and his aides, reported Tom Raum in the Huffington Post, were ecstatic about the results. As far as I can tell, there were none, at least none that were good. Turkey has continued its drift towards an Islamic foreign and domestic policy. The Organization of the Islamic Conference is already meeting in Istanbul, and Dr. A'jad will arrive there on Sunday. Believe me, he will be royally welcomed ... and raise tremors among the declining moderate populace.

As with the meanings he conveyed to the Turks, Obama is to be judged with reference to the Iranians on what messages he has sent them. To the people in the streets, to the middle class and to the students--the only hope for Iran--he has shown them, frankly, his behind. Not a statement of solidarity. Certainly not material support. He is still apologizing for the overthrow by the C.I.A. of Iran's prime minister, Dr. Mohammed Mossadegh, in 1953. That was 56 years ago, for God's sake. Still, his apologies have gotten him nowhere and will get him nowhere. 

It is possible still that the democrats and moderate Muslims of Iran will win, not this year or even next year. One thing we know is that the American president has set them back aplenty. And that is a result of his curious empathy for Islam not simply as a religion but as a way of politics in the world.