The horrendous bombing at Domodedovo Airport was quickly eclipsed by the Egyptian uprising, but both are incidents in the new world war. That war began on Sept. 11, 2001, with an act of violence as specific as the assassination of Franz Ferdinand in Sarajevo in August 1914 that started World War I.

World War II also began with specific acts of violence — the invasion of Poland and the bombing of Pearl Harbor — but the Cold War, or “World War III,” did not. The Cold War, anomalous in many respects, was about the containment of violence rather than its use.

This new world war will, at the very least, define the first half of the 21st century (already 20 percent complete), just as the Cold War defined the last half of the 20th century. World War I and II were relatively classical with clearly defined enemies and uniformed troops clashing on battlefields. The Cold War was amorphous and only sporadically violent. The New War is also amorphous but more than just sporadically violent without approaching the levels of World War I or II. But if the war widens to include a nuclear Pakistan and India, it has the potential to dwarf its predecessors.

The West had the dubious distinction of being the main arena of the last three world wars, but this one is centered elsewhere, in the Muslim world, a struggle among a daunting array of opponents — aging tyrants and hi-tech youth, Islamists and democrats, mixed with traditions of religious and ethnic hatred that are impossible to sort out. Though there are real grievances against the West, the conflict is ultimately a civil war within the Muslim world. The violence done to New York skyscrapers, Domodedovo and the Moscow and London subways are almost collateral damage.

The war may be centered in the Muslim world, but it’s a moving center. Tunisia one day, Egypt the next, with tomorrow being anyone’s guess. Some commentators have worried aloud about the Egyptian “contagion” spreading throughout the Arab lands. They’re worrying too small. Central Asia is also ripe for revolts of the Egyptian variety. The two largest Central Asian countries, Kazakhstan and Uzbekistan, are ruled by elderly despots who have been in power since the Soviet days. Kazakh President Nursultan Nazarbayev has been working to be made president for life, a position he is already reconsidering in light of recent events in Egypt and Yemen. Uzbek President Islam Karimov has for the first time mumbled something like an explanation, if not an apology, for the massacre of protestors in the city of Andijan in 2005. In fact, Central Asia already has its own model for toppling tyrants in Kyrgyzstan, which has now become the region’s first parliamentary democracy after it sent its corrupt dictator packing.

Many think that the turmoil in Egypt cannot ultimately be good for the United States, not to mention Israel. Likewise, turmoil in Central Asia cannot be good for Russia. As Washington did, Moscow will no doubt opt to support aging tyrants in order to keep terrorism down and avenues of commerce open. But the day of reckoning will be worse for Moscow because Muslim unrest and violence will not only permeate its borders but arise from with the Islamic segment of Russia’s population. The Kremlin has two essential tasks now: to modernize its economy and society and to get on the right side of history, the winning side in World War IV, while there’s still time. Failure to do either will prove ruinous.