Secretary of State John Kerry has spelled out the moral case for attacking Syria, and analysts increasingly agree that President Obama has already resolved to launch a military strikein response to the Syrian regime's apparent use of chemical weapons banned under international treaties.

The justification for hitting the regime of embattled Syrian President Bashar al-Assad is clear. Obama last year called the use of chemical weapons a "red line" that would justify foreign intervention, and Kerry said there was ample evidence that Syrian forces were behind a poison-gas attack that killed hundreds of people, including civilians, last week.

How and when the U.S. and its allies might go after Assad's military are open questions, however. Here are four predictions of what the world can expect:

1. The attack could come within days
The U.S. already has four guided missile destroyers in the eastern Mediterranean within range of Syria. NBC News is reporting that the strikes could begin as early as Thursday. "Officially, President Obama has not yet given the order to launch those attacks but I can tell you that officials here at the Pentagon are operating as if this is, in fact, a done deal and they expect attacks as early as perhaps the end of this week or early next week," Jim Miklaszewski, NBC's chief Pentagon correspondent, said on the air early Tuesday (via Talking Points Memo).

2. The strike will include a volley of cruise missiles
The nature of the strike is easier to predict than the timing, say Karen DeYoung and Anne Gearan at The Washington Post. It will "probably last no more than two days and involve sea-launched cruise missiles — or, possibly, long-range bombers — striking military targets not directly related to Syria's chemical weapons arsenal," they say.

3. Obama won't wait for the U.N.'s approval
With Russia — Assad's key ally — and China blocking any move against Syria by the United Nations Security Council, look for Obama to "bypass the U.N. and, as in the case of the 1999 NATO air war in Kosovo, assemble an ad hoc international coalition to support military action that would provide legitimacy, if not strict legal justification, for intervening to protect Syrian civilians," says The New York Times in an editorial. But if Obama does forgo the U.N., the Times warns, he'll need strong endorsements from the Arab League and the European Union.

4. The aim will be to send a message — not join the war
Pentagon officials are telling reporters that the strikes will be aimed at sending Assad's government an emphatic message that using sarin nerve agent and other outlawed chemical weapons is unacceptable. The aim, NBC News says, will not be degrading Assad's military capabilities or turning the tide of the country's two-and-a-half-year civil war. Indeed, military experts say the Syrian regime would likely survive a limited bombing campaign.

That approach meets the approval of war-weary people across the political spectrum who share Obama's reluctance to get the U.S. involved in another Middle East war. "Given that President Obama has — rightly, in my judgment — decided over these past two years plus that the horrible toll of death and refugees in Syria's civil war does not justify significant U.S. military intervention," says James Joyner at Outside the Beltway, "I trust that a symbolic strike will be the end of it."