Obama makes case for punishing Syria over gas attack

Syrians prepare for attack

In Damascus on Wednesday, people left homes close to potential targets as US officials sketched out plans for multi-national air strikes on Syria that could last for days. UN chemical weapons experts completed a second field trip to rebel-held suburbs searching for evidence.

But as UN chief Ban Ki-moon appealed for unity among world powers and sought more time for the inspectors to complete their work, Washington and its European and Middle East allies said their minds were made up and that Assad must face retribution for using banned weapons against his people.

Syria's government, supported notably by its main arms supplier Russia, cried foul. It blamed rebel "terrorists" for releasing the toxins with the help of the United States, Britain and France, and warned it would be a "graveyard of invaders."

Syrian officials say the West is playing into the hands of its al-Qaida enemies. The presence of Islamist militants among the rebels has deterred Western powers from arming Assad's foes. But the West says it must now act to stop the use of poison gas.

Britain pushed the other four veto-holding members of the UN Security Council at a meeting in New York to authorize military action against Assad to protect Syrian civilians - a move certain to be blocked by Russia and, probably, China. The meeting ended without a decision.

The United States and its allies say a UN veto will not stop them. Western diplomats called the proposed resolution a maneuver to isolate Moscow and rally a coalition behind air strikes. Arab states, NATO and Turkey also condemned Assad.

But British Prime Minister David Cameron was forced on Wednesday to push back his timetable after coming under fierce domestic and international pressure, and it was unclear how that might affect any Syria attack plans.

Just a day after recalling Britain's parliament to vote on how to respond to Syria's suspected use of chemical weapons, Cameron was ambushed when the opposition Labor party said it wanted greater parliamentary scrutiny and rebel lawmakers in his own ruling Conservative Party said they would oppose him.