Let me pose this a different way for Comrade Chait.
The leadership of ISIS is in a building having a meeting. We know they are there, we know what they are planning and we know when it will take place. we also know that based on our existing knowledge, several thousand people will die in the attack.
In the courtyard, two children are happiy playing. If we take out the leadership in a bombing raid, the children will definitely be killed.
In this scenario there are a couple of options. Don’t bomb, let the event happen and politically weasel your way of of it. Don’t bomb, let the event happen and deny any knowledge that something is going on. Or bomb, acknowledge that there was collateral damage, but in the process you fixed the problem.
Governments will always choose the course of action/inaction where the costs are not directly attributable.
In your scenario, the death of the two children would be directly attributable to an action decision,
whereas not acting could not be directly attributable as the cause of the thousands killed.
Leftist/Government people would pick the latter, every time.