Refer back to Penguin's response. Israel is not exposed on a balcony. They're on the other side of a massive actual and metaphorical wall that enemy fire can hardly ever penetrate.Given that the odds of your crazy neighbour actually presenting a risk to your family are very close to zero, is it still acceptable to shoot your crazy neighbou's kid?
You seem to be fixated on trying to turn the situation into a black and white, simple as apple pie, issue. It's easy to decide who's right and who's wrong as long as you claim you can predict the future -- that there is nearly zero chance of this or nearly zero chance of that. And I don't begrudge you what you are doing. The human temptation to shirk complexity of any kind -- let alone moral complexity -- is universal. We all try to simplify things. But sometimes simplicity is not reality.
If your neighbor puts his child on his lap and then tries to shoot into your nursery to kill your children, that is not a morally unambiguous situation. It most likely cannot be resolved so that you remain morally pristine no matter what you do. There is no "high road" in such a situation. None.