What they want in Syria?

I don't understand what the NATO, wants from Syria.
Officially they say that will shoot some rockets and that's will be all. No toppling of the regime.
Assad in this case will duck from rockets and will continue to kill his people.
If islamists will win in Syria  will be bad for West, if Assad stays in power is bad for West. It is a lose lose situation.
The only win-win situation will be to freeze the conflict and to allow development of a democratic society.
By democratic society I mean, the people should struggle for power with peacefull means.
A good solution is to sent UN troops to provide a barrier between combatants.

I think that either the western politicians are liars, and their purpose is to topple the Assad regime, and they want to escalate slowly the conflict, either they are stupid and they think they can solve the Syrian problem with some rockets in matters of days.They think that we are idiots, and we will buy this.
These politician have forgotten that World War I should have lasted few months, and the Afghan and Iraq wars should have ended few years ago.