If someone started firing rockets on Manhattan or Peoria, I would expect the United States to take military action to stop them and the United States would be completely justified in doing so. This would be true whether or not the rockets were successful at killing many Americans. It would, in almost all circumstances, not matter why these attacks were being launched. For example, the fact that they might be launched by groups with significant legitimate past or present grievances against the United States would make no difference.
Hamas attacked Israel with multiple rockets. The rockets were fired from Gaza, an area under the effective control of Hamas. Rockets are not rocks thrown by teenagers; multiple rocket attacks are an act of war. An Israeli military response to destroy Hamas and/or its ability to attack Israel was appropriate and justified.
So far, this issue should be an easy one. In fact, if someone disagreed with the foregoing, I would have to conclude that they are either disconnected from reality or an apologist for Hamas.
The reality on the ground is both more complicated and tragic than the hypothetical at the beginning of this diary and adds another dimension to the issue.
Gaza is a densely populated area, approximately as densely populated as Boston or DC. When an area like this is attacked by a modern military, civilian casualties will be significant. It is to Israel's credit that they have taken steps to minimize civilian casualties, including providing warnings of (some) attacks; but it should surprise no one that these steps have been of limited effectiveness. (Though the death toll in this invasion of Gaza has been significantly lower than the death toll in 2009, despite apparently being focused on more highly urbanized parts of Gaza than the 2009 attack.)
Suggestions I've read here in recent days that Israel is "genocidal" are some poisonous blend of obscene and insane, but as I write this the death toll of Palestinians in Gaza was last reported at 817, the significant majority of which were, by all accounts, innocent bystanders, including a significant number of children. I can also predict with unfortunate confidence that no matter what attempts Israel makes to minimize civilian casualties the death toll will continue to rise as long as the combat continues and will continue to be overwhelmingly innocent bystanders.
Hamas has continued to fire rockets at Israel and rejected one option for a mutual ceasefire and it should be uncontroversial that Hamas bears a significant share of the blame for the deaths of Palestinian civilians. For those whose goal is simply to stop the deaths, Hamas' rejection of that last Israeli ceasefire should be the subject of unequivocal condemnation; for those who have another goal for which they are willing to see more die...it is understandable that they would support continued combat.
That Hamas bears a significant share of the blame does not absolve Israel of its responsibility for the deaths of hundreds of Palestinians. And, in thinking about its course of action, Israel does need to take the potential for Palestinian civilian deaths into account.
I think, in light of Hamas rocket attacks, and despite the resulting tragedy, the Israeli response was and is justified. But it is neither as uncontroversial nor as one-sided an issue as it would be were the death toll significantly lower, or the proportion that were not combatants significantly higher or the Hamas attacks on Israel more dangerous.
However, it is important to recognize the tragedy that results from even justified military action. And it is nothing less than obscene to cheer the deaths of the innocent.
There is another issue that need be addressed here:
Justified does not necessarily mean smart. When Hamas started launching rockets at Israel, it was pretty close to a well-deserved demise. It had agreed to a Palestinian unity government because it was unable to pay salaries. It was increasingly unpopular among Palestinians. Its ability to obtain additional supplies and arms had been crippled, partly by the determination of Egypt to end Hamas, but also by the dissolution of Syria and preoccupation of Iran. The effect of Israel's attack has been to somewhat continue the degradation of Hamas' military capabilities but massively (and understandably) increase its popularity.
It is probably time for Israel to propose a ceasefire to end this, similar to the ceasefire that ended the 2009 Gaza conflict. (That is, Israel will cease fire for some period of time and if Hamas does the same proceed to withdraw its ground troops from Gaza.) That will lead to an immediate halt in the deaths of Palestinian civilians. Because of how badly weakened Hamas is, though, I suspect that Hamas will again not accept and Israel will be faced with the choice of resuming active combat or just ignoring Hamas attacks for a time.
The question for Israel at that point will be: how long will it take Hamas to run out of rockets and how many Israelis will die before they do? And, the question, for those who would suggest Israel take this course of action is what should cause Israel to once again resume active combat against Hamas?