There’s an anniversary this week we might do well to recall. On May 29, 1453 – just 555 short years ago -- troops led by Mehmed II broke through the walls of the ancient Christian capital of Constantinople.

Mehmed the Conqueror – as he would be known from that day forward -- rode triumphantly into the city on a white horse. Soon, churches would be converted into mosques. Constantinople would become Istanbul.

“For the West this was a dark moment,” writes historian Efraim Karsh in his masterful book, Islamic Imperialism. “For Islam it was a cause for celebration. For nearly a millennium Constantinople had been the foremost barrier – physically and ideologically – to Islam’s sustained drive for world conquest and the object of desire of numerous Muslim rulers.”

Mehmed cast himself as not just as a master builder of the Ottoman Empire, but also as the caliph – the supreme spiritual and temporal ruler of all the world’s Muslims, chosen to “act as Allah’s Sword ‘blazing forth the way of Islam from the East to West.’” He would go on to conquer Greece, Serbia, the Balkans south of the Danube and the Crimean peninsula. His grandson and great grandson would extend the caliphate to include the Levant, Egypt, the Arabian Hijaz including the holy cities of Mecca and Medina, Iraq, North Africa, and most of Hungary.

The desire to conquer the world – or even just one’s neighbors -- is hardly an Islamic invention. Genghis Khan is not a name: It’s a title. It means “universal ruler.” The man history knows as Genghis Khan believed it was his divinely ordained mission to lead the Mongols to global domination.

And he loved his work. “Man's highest joy is victory: to conquer his enemies,” he said, “to pursue them; to deprive them of their possessions; to make their beloved weep; to ride on their horses; and to embrace their wives and daughters.”

Upon entering the city of Bukhara in 1220 he proclaimed: “If you had not committed great sins, God would not have sent a punishment like me upon you.”

Genghis Khan was a pagan, a shamanist, as was his descendant, Hulagu, who in 1258 conquered Baghdad -- among the world’s most sophisticated cities at the time -- and executed the reigning caliph.

A few years ago, Osama bin Laden, on one of his audio tapes, compared Colin Powell and Dick Cheney to Hulagu, saying they had inflicted more damage upon Baghdad in the 1991 Gulf War than had the Mongol king. Bin Laden may take some consolation in the fact that Hulagu’s son, and many other members of the ruling Mongol elite, eventually embraced Islam. (Whether the same will be true of the heirs of Powell and Cheney only time will tell.)

For centuries, the world was spun by what Nietzsche called the “will to power.” Africa and the Americas were conquered by European Christians. Napoleon was crowned emperor by the Pope. Tojo fought to expand Japan’s empire. Mussolini, Hitler and Stalin conquered in the name of totalitarian ideologies.

In recent years, however, the West has rejected not just Genghis Khan’s perspective on the joys of conquering, but the very idea of empire building, at least through martial means. Indeed, so thorough has this rejection been that many Americans and Europeans can no longer imagine anyone continuing to harbor such ambitions.

On that basis, they further assume that violence and terrorism – from the attacks of 9/11/01 to the missiles raining on Israel to the suicide-bombings in the marketplaces of Iraq – must be a response to oppression or occupation or some other “legitimate grievance.” History suggests otherwise. So, too, do the leaders of the various modern militant Islamist movements.

“We are in the process of an historical war between the World of Arrogance and the Islamic world,” Iranian President Mahmoud Ahmadinejad has declared, “and this war has been going on for hundreds of years.”

“We are not fighting so that you will offer us something,” said Hussein Massawi, a former leader of Hezbollah. “We are fighting to eliminate you.”

“Rome will become an advanced post for the Islamic conquests, which will spread though Europe in its entirety, and then will turn to the two Americas, even Eastern Europe,” Yunis al-Astal, a Muslim cleric and Hamas parliamentarian has pledged. “Very soon, Allah willing, Rome will be conquered, just like Constantinople was, as was prophesized by our prophet Muhammad."

Mehmed the Conqueror would understand, though his defenders would say he was never quite as radical as are the Islamic warriors of the contemporary era.