Israel will not get a working relationship with any future regime just because we help topple Assad because they are still going to hate Israel, we will always be the zionist enemy. We have no idea who will replace Assad because most likely once he is gone there will be a fight for power and the current unity will end so we have no idea who we are dealing with. Then of course is the issue of how do we topple him without military intervention, what are we going to do recall our ambassador or place sanctions on Syria at a political lever we are helpless. Assad is also good for Israel because as long as he is still running the country there is stability under a single strongman rather than a chaotic fight for power like we saw in Iraq once we got rid of their strongman. The current fighting is actually benefitting israel because as well as tearing the country apart he is wasting all his military hardware on his people rather than on Israel if a war were to break out in future and the economy is in tatters so there will be no money to rebuild the military afterwards so for us its great. Unfortunately soon enough Israel will be dragged into a conflict in either Lebanon or Syria. We will continue to destroy arms convoys, we have no choice unless we want Hezbollah armed with things like anti aircraft missiles and eventually Assad is going to do something about it. He might fire missiles onto Israel in which case we will retaliate and smash his military and bring about his downfall. If he used Hezbollah and they provoke a war then if they fight from Syria we will attack them and probably Assad as well. If they attack from Lebanon then we will have another Lebanon war so either way its looking like Israel will be dragged into this war. So prepare to eventually see Israeli jets dropping bombs on Lebanon or Syria.
Donald Trump: Israeli settlement construction in West Bank should 'keep going' (Haaretz)