Dave, your use of the word "war" suggests that the Israelis are fighting a war aginst a Palestinian state.

This was an act against a terrorist (the member of a terrorist organisation, not a general of an army of a foreign power) within the territory of Israel, which resulted in the deaths of civilians ostensibly under Israeli sovereignty and the responsibility that this entails.

You're using an incorrect standard, to mask the fact that the Israelis, in killing a known terrorist, also indiscriminately killed seven children.

You say a just war has its costs. What about a counter-terrorist action? Can you imagine the outcry that would erupt if this had happened in the United States, and seven children were killed during a counter-terrorist operation?