Initially, America wanted to resort to military action as a punishment for a chemical attack by Syria, an attack they have presented precious little proof was conducted by Assad forces.
Foiled by a lack of appetite from the major International players for another Middle East conflict and a UN veto by China and Russia, the Americans struggled to get the backing for their military action but now the reasons for wanting to fire missiles at Syria have changed and it has become about Syria's Chemical weapons and Assad handing over information regarding his Chemical weapon stash.
US Secretary of State John Kerry has rejected Syria's pledge to hand over information on its chemical weapons in 30 days, saying 'the words of the Syrian regime in our judgement are simply not enough' and warning that the US could still launch a military strike if Syria's President Bashar al Assad reneged on his promises.
Syria has sent a letter to the UN signing up to the Chemical Weapons Convention which fulfils the first part of the Russian four point plan with the second stage is for Syria to declare what chemical weapons it has which the Americans want to happen in less than the usual 30 day time frame.
This does smell of America picking any pretext for intervention, war and regime change and hoping that they can make the conditions for an invasion more likely, UN agreement or no agreement.
The bottom line is Obama wants his war and if he can't get it one way, he will get it another way and this will be accomplished by an ever changing list of demands, potential catch 22 situations and ever smaller hoops to jump through and the first time a time line slips, the America military will do what they have been sent there to do, regime change.
Of course it is a good thing that chemical weapons are being destroyed but this is moving the goalposts to justify aggression and they will keep moving them until they get it.
This is about the Us shifting the entry point for war from blaming Assad for a chemical weapons attack to saying he's holding chemical weapons back and we have to attack before he uses them again. Exactly like Saddam Hussein and his huge pile of WMD's and we know how that turned out.