Syrian Missile Crisis

The prospect of Iran developing nuclear weapons is generally taken to be half the problem. The second problem they would be taken to have is to develop a missile delivery system that can hit Israel. But do they really have to? Is it not entirely conceivable that they will simply place it in Iran or worse, with Hezbollah in South Lebanon and use a simple delivery system that really does not have to be long range? There is no way to prevent this, and it might even be difficult for Israel to know about such weapons even in Syria.