Not the usual hand-wringing over the "plight" of this group or that, but a bit of game playing. Think about Gaza as though you were playing some advanced version of Risk.
If I were some up-and-coming military strategist in Iran, and wanted to make a name for myself, I'd suggest something along these lines:
Instead of having our proxies attack Israel at their own convenience, and get smashed, lets try having the less valuable asset (Hamas) attack the Jews in the south, using a limited, but noticeable, number of long-range rockets. We can supply a limited number of the longer range rockets in order to get their attention.
When the Jews inevitably put together a counter attack, in significant force, we have Hamas fight a holding action designed not so much to provide a credible counter force, but to tie down the largest numbers of the Jewish military. When the fighting has reached some leveling-off point, we order our stronger asset, Hezbollah, to attack from the north as hard as possible. The newer (Chinese) rockets have enough range to reach Tel Aviv, and with the army tied up in the south, we can mount a highly effective attack for a much longer time, possibly adding to that, a limited land invasion of our own. Or if we can convince them it might work, perhaps the Syrians will get in and help.
I would not expect this to defeat Israel, but to severely weaken and demoralize it in preparation for an air or sea attack on Tel-Aviv using nuclear or biological weapons. Still, you never know, we might get lucky, and even if Gaza is completely depopulated, and Hezbollah is pounded back to the stone age, it's little enough skin off MY nose.
You have to try to think like the enemy.