NATO begins bombing Syria. Naturally Syria begins bombing Israel.
The game plan goes something like this. NATO begins bombing Syria. Naturally Syria begins bombing Israel.
1. Because it's Assad's best chance to make the conflict seem to be one between a Muslim leader and Israel, rather than between fellow Muslims.
Saddam bombed Israel for the same reason during the Gulf War. It shifted the focus away from his invasion of Kuwait and won him Muslim sympathy.
2. Because Israel won't be able to fight back.
Right now if Assad begins hitting Israeli targets, Israel is free to hit Syrian targets. That will change drastically once NATO is operating on the ground.
Israel was not allowed to go after Saddam, even while it was being attacked because that would have undermined the position of the Gulf War coalition in the Muslim world.
The same thing is very likely to happen with Israel and Syria. NATO will not want to avoid associating the conflict with Israel because of Muslim sensibilities. Assad will want to make this conflict about Israel and he will know that Israel will have trouble retaliating once Syrian airspace is controlled by NATO and Israeli aircraft will be barred from entering.
The gestures will be futile, but they will be a reminder that Israel's ability to defend itself has been passed over to the forces of international appeasement.