Salifism

The morally correct answer is no. But the following grim yet practical option should at least be discussed. 
The element of surprise is one of the key tactics in any war, whether it be a military war, an intelligence war, an information war, a cold war or a broad sweeping moral battle.
Syria is now in the cross-hairs of a Pentagon seemingly hell bent on war. Whether Donald Trump can or even still wants to resist this, is anyone’s guess.
This is why Syria, in close cooperation with her allies must take the first decisive step.

The contemporary foreign policy of the Russian Federation can be characterised as a pragmatic defence of self-interests along with the interests of its allies. All of these policies tend to be conducted within the framework of international law. In fact, Russia often finds herself having to define the precepts of international law to other nations who frequently violent it.