While the world's attention was focused on Boston and North Korea, the conflict in Syria entered a new phase -- one that threatens to embroil its neighbors in a chaotic way and pose complex challenges to the Obama administration.
What began as a protest movement long ago became an uprising that metastasized into a war, a vicious whirlpool dragging a whole region toward it.
Many analysts believe the United States can do little to influence -- let alone control -- the situation. And it could make things worse. Fawaz Gerges of the London School of Economics argues against the United States "plunging into the killing fields of Syria ... because it would complicate and exacerbate an already dangerous conflict."
Others contend that if the United States remains on the sidelines, regional actors will fight each other to "inherit" Syria, and hostile states such as Iran and North Korea will take note of American hesitancy. They say inaction has given free rein to more extreme forces.
And in the wake of the strikes against Damascus, apparently by Israeli planes, critics argue that Syrian President Bashar al-Assad is now more vulnerable than ever and U.S. intervention could help finish him off.
Republican Sen. John McCain has revived calls for a no-fly zone. And introducing legislation to arm the Syrian rebels in the U.S. Senate on Monday, Democratic Sen. Robert Menendez said: "There will be no greater strategic setback to Iran than to have the Assad regime collapse, and cause a disruption to the terror pipeline between Tehran and Hezbollah in Lebanon."
But more than two years since the revolt against al-Assad began, regional analysts say Syria is in danger of becoming the next Somalia, which collapsed into fiefdoms 20 years ago and has been stalked by anarchy, terrorism and hunger ever since. Except Syria would be worse. Its religious and ethnic fault lines extend across borders in every direction; Somalia's anarchy was largely self-contained. Somalia never had chemical weapons, nor the missiles and modern armor that make Syria one of the most crowded arsenals in the world.
And unlike Syria, Somalia was never central to a titanic struggle between different branches of Islam: Sunni and Shia.
Given that background, here are five reasons Syria's war suddenly looks more dangerous.
1: Israel and Hezbollah's proxy war
For two years, Israel has looked on with growing anxiety as brutal repression in Syria has become de facto civil war. Now a high-octane game of regional poker is under way. The Israelis have not admitted carrying out the devastating strikes of last week, but U.S. officials tell CNN they have no doubt Israel was responsible.
Why would Israel suddenly become an active participant? While much has been said about President Barack Obama's "red line" -- that the use of chemical weapons in Syria would make him reassess U.S. involvement -- the Israelis have a different threshold: the transfer of advanced missiles to al-Assad's ally, the Shiite Lebanese militia Hezbollah.
Their main worry, U.S. officials say, was the possible transfer of Iranian-made Fateh-110 missiles, whose accuracy would pose a new threat to Israel. A consignment of these ballistic missiles had recently arrived at Damascus' airport. Similarly, the second Israeli strike before dawn Sunday was on a "research facility" near Damascus where weapons destined for Hezbollah were kept.
According to Jane's Intelligence, Iran's Defense Ministry reported the test firing of an upgraded Fateh-110 last year, and the Iranian Aerospace Industries Organization claimed it had a range in excess of 180 miles (300 kilometers.)
Israel's motive was not to degrade the Syrian military. It was about sending al-Assad a message (copied to Iran and Hezbollah): "If you try to raise the regional stakes by passing a new generation of short-range ballistic missiles to Hezbollah, the response will be swift and severe."
Gerges, author of "Obama and the Middle East," told CNN that we are seeing "an open-ended war by proxy. ... On the one hand you have Israel, regional powers and the Western states; on the other hand you have Iran, Hezbollah and Syria."
Middle East analyst Juan Cole agrees, writing on his blog: "It is not that the Israelis and Hezbollah are in any direct conflict, but they are gradually both becoming more active in Syria on opposite sides. It is an open question how long this process can continue before the conflict does become direct."
One miscalculation could provoke a wider escalation.
The stakes for Hezbollah are enormous. For nearly 30 years, it has been sustained by Iranian and Syrian support. If Syria becomes a Sunni-dominated state, Hezbollah's "rear-base" vanishes, and suddenly it looks more vulnerable to its archenemy Israel, one of whose strategic goals is to counter the growing missile threat from the north.
Military analysts believe Hezbollah has an arsenal of some 50,000 missiles and rockets, supported by a sophisticated, hardened infrastructure that would be even harder to uproot than during its last conflict with Israel in 2006. Little wonder that Israel has deployed two of its Iron Dome missile-defense batteries in its northern cities.
Will the Syrians retaliate for the strikes, which they describe as a declaration of war by Israel? To do so would divert resources from the regime's battle for survival. Not to do so would convey an image of weakness in the face of the "Zionist enemy."
Al-Assad has a history of not retaliating against Israel, most notably when the Israelis took out what was purported to be a Syrian nuclear installation in 2007. According to Cliff Kupchan with the Eurasia Group, Israel has calculated that "Bashar al-Assad is incapable of fighting on two fronts, that Iran will keep its powder dry for a possible future conflict over its nuclear program, and that Hezbollah will not attempt significant retribution without approval from its sponsors."
But one risk to Israel is that in weakening the Assad regime, it may strengthen some of the best organized and most potent rebel factions: jihadist groups such as the al-Nusra Front, which has already declared its affiliation with al Qaeda in Iraq.
2: More than ever, it's sectarian
In the early days of the Syrian uprising, people who were anti- and pro-regime shared one common dread: that Syria would descend, Bosnia-style, into sectarian horror. Now, in the fight to prevail, that has become a reality.