The U.S. has been very slow to provide arms to the Syrian rebels apparently because it is very concerned that those arms will fall into the hands of the Islamists, who might then dominate the struggle to oust Assad.
I believe that it makes no difference as long as Assad is ousted. If Assad survives, then Hezbollah will be strengthened, as will Iran's stature in this part of the world. And if Hezbollah is strengthened, then the Arab-Israeli relationship will suffer enormously.Imagine a direct pipeline for sophisticated arms from Iran through Syria to Hezbollah. On the other hand, regardless of whether the pro-democratic forces or the Islamic forces prevail in Syria, both Hezbollah and Iran will suffer. The impact on Hamas could be significant, but at least Israel has the opportunity to block the flow. The Islamic forces in Syria are Sunni and should have no love for the Shiite Hezbollah. Of course we, the U.S., would prefer that the pro-democracy forces prevail. But if we pursue this objective while risking the possibility that the resultant timidity leads to the success of the pro-Assad forces, then we have lost a great deal. Our options are not the best, but as long as Assad is ousted, the region will benefit. An Islamic Syria will be bad for Israel, but better than an Assad-controlled Syria.