President Barack Obama, with Vice-President Joe Biden, has asked Congress to back his plans. Photo / AP
Short of support on Syria, Obama has turned to a reluctant Congress.
Why did US President Barack Obama delay planned air strikes on Syria after the chemical attack last month? And what situation does he find himself in now?
Different factors and political calculations must have come into play after the historic parliamentary defeat of the President's ally David Cameron in Britain. Some swirling around are:
1) Slow it down, build the case The delay could have been recognition that the aftermath of the chemical attack on Ghouta, Damascus, was rushed and mishandled.
Now he can get the G20 summit in Russia out of the way, try to build support for action in Congress and among the public and possibly wait for the UN report - although Secretary of State John Kerry tried to pre-empt the UN report by speaking of evidence from "first responders".
The political climate for strikes could become more favourable as more information emerges about the gas attack.
Yet the delay could also mean opposition to intervention has time to grow and consolidate and the Assad regime is working hard to influence opinion against action. It has seen cracks emerge in the coalition ranged against it, and with Russia's help is trying to widen them.
The President is taking a lot of heat now - appearing weak and hesitant to many - but that impression could easily shift once an air strike was under way.
2) The question of political cover Military action against Syria is unpopular. The US is war-weary as shown by opinion polls. People are wary of mistakes over Iraq being repeated. Getting Congress to approve action - if possible - shares the load rather than Obama shouldering all the responsibility.
3) Obama needs all the help he can get It's also clear that Obama has never looked more isolated, ineffective and indecisive. Britain doesn't have his back on this one and support from France, Nato and the Arab League has ranged from wobbly to lukewarm. The US has a bag of bad memories from previous Middle East interventions. Plenty of pro-action commentators believe limited strikes are insufficient and a more concerted blow, in the style of Kosovo, is what's required. Others worry that limited action could make the conflict worse. Obama's own chairman of the Joint Chiefs of Staff, General Martin Dempsey, has warned repeatedly of the risks and costs of getting involved in Syria.
4) Assad put on notice In a way, Obama has achieved a major purpose of the limited strike he plans, or "shot across the bow" as he referred to it. (President Bashar al-Assad has, of course, yet to feel the "punishment" side of the equation.)
In clearly threatening war, including saying what would be hit, and shifting warships into position, Obama has warned Assad and put him on notice not to use chemical weapons. The delay means Assad has been given a period of time to behave. Meanwhile, the US now has twice as many destroyers available in the region than it had last week. Could the strike be bigger than outlined?
However, Assad has shown no sign of responding in the way Obama would prefer, challenging the West for proof his regime was behind the gas attack, warning of regional war and putting pressure on France ahead of a parliamentary debate tomorrow.
6) Doing what he said Obama has had a difficult year, particularly with disgruntled liberal supporters over the NSA spying programmes and whistleblowers. As a senator Obama had argued that Congress should authorise military action. Now he can avoid the charge of hypocrisy and appear to stand for a principle.
7) A welcome defeat? Some might suggest (and have) that Obama would prefer Congress to vote against taking action - giving the President a way out. The thinking goes that ideally, Obama would appear to prefer to simply threaten Assad to the negotiating table than bomb him there. Or bomb him only slightly. The President knows how messy an entanglement in Syria could be. The Wall Street Journal reports the Obama Administration would prefer to contain the civil war - but without the use of chemical weapons - until there is a gradual move towards a negotiated end. It does not want a collapse of the Assad regime because of the jihadi elements among the rebel groups. However, ducking behind a Congress rejection and taking no action regardless would make Obama look worse than weak with lame duck status solidifying on his shoulders.
8) War and political prospects Delaying gives the Administration some time to squeeze reportedly reluctant congressmen and women into falling into line on a war vote.
At least some Republicans are reportedly against giving approval. They see Syria as not involving America's direct interests and do not want to risk aiding rebels with al-Qaeda links. There is no clear aggression against US targets or interests in this case.
But should Republicans vote against and Obama gets through the action relatively quickly and politically unscathed, a no vote could cause political problems down the line with mid-term elections next year and the 2016 presidential campaign.