Terror and Charity
That said, it's impossible to look at the military functions of these groups as a mere sideline to this more wholesome work. Undoubtedly, both Hezbollah and Hamas (prior to Hamas actually becoming the government) take full advantage of the weakness and failure of the Lebanese and Palestinian governments, and their "humanitarian" work serves to win supporters among the down and out—people so grateful for the sustenance they receive that they would never dare bite the hand that feeds them even when it means countenancing, say, a salvo of missiles into northern Israel or the immolation of a pizza parlor in Tel Aviv.
As can be seen in the recent war between Israel and Hezbollah, the latter group exacted payment for their support of the southern Lebanese Shiites by using the very people they provide medical care for as human shields. Hamas operates under a similar philosophy in the Palestinian territories.
But, even putting aside the callous treatment of their own supporters, neither Hezbollah nor Hamas could ever be fairly described as a "humanitarian" organization. And that would be true no matter how many hospitals or kindergartens they build for their suffering people.
Simply put, you can't simultaneously be a humanitarian and wish for the destruction of an entire country and its people. There is nothing humane about wishing harm on fellow human beings, and no amount of charity work will ever make up for the carnage that results from putting that philosophy into action.
The tendency is to look at groups such as Hamas and Hezbollah as mixtures of good and bad—taking care of their people while wreaking havoc across the borders. This is a deeply dangerous and misleading point of view.
It is quite easy, for example, to imagine groups in the Palestinian territories and southern Lebanon wholly devoted to social service, and propped up by their petro-rich brethren in the Gulf to that end. It is impossible, however, to imagine the opposite: paramilitary organizations supported by the largess of outside powers wholly devoted to terrorism against Israel. It becomes clear that the charity work of Hamas and Hezbollah is simply a means to achieving their actual, bloody goals. Without it, the native Arab and Muslim populations would never tolerate their presence.
The fact that so much support flows to these groups from Iran, Saudi Arabia, Syria and elsewhere is proof of bad intentions. If the Muslim powers at large wanted to give humanitarian aid, they would do so. By supporting Hamas and Hezbollah, they merely show that while they understand the importance of the carrot, they're ultimately only interested in the stick.