If Hezbollah DOES succeed, it will be just as with the HAMAS led PA. They will be isolated save for Iran and Syria and all foreign assets will be frozen, etc. Lebanon is much larger than Gaza and much, much more diverse so that the populace will not stand for the enforced poverty of having a terrorist govt. In addition, any Hezbollah takeover will be far from peaceful as has been shown by the riots all this week.
As for Israel's position if Hezbollah should succeed, Israel will annihilate them on a scale unseen thus far.