The Smallest Minority on earth is the individual. Those who deny individual rights cannot claim to be defenders of minorities. - Ayn Rand
Since I have yet to develop my telepathic abilities I have to guess as to whether or not you 'really' intend to do me harm. Odds are that I'm going to guess that you do and react 'appropriately'.
In Israel's case they don't have go guess since both Hamas and Hezbollah have publicly and repeatedly stated their goal of destroying Israel. You can ignore that sort of talk if you think the speaker is just a harmless crank, but once they show any sign of being able to try to follow through...
However, the analogy is far from perfect.
While citizens are living under the State, which has the monopoly of force (at least ideally), there is not higher, real, authority above States.
In the end, what matters for international relations is intentions and capabilities rather than rights and laws.
Thanks for the link; I'd note that Instapundit linked a few days ago to a report that the state of Michigan had adopted a new legal standard in which a person is under no legal duty to retreat under threat of murder, severe bodily violence, or sexual assault even in public. The traditional legal standard in the US has been that you are under a duty to retreat in public, but under no such duty in your own home. As I understand English law, there you are under a duty to retreat and then some, even in your own home, which seems crazy to me, but then I am definitely not an English lawyer.
In addition to the Cooper quote there is this quote by Heinlein I think is appropriate.
This also reminds me of another quote which I will use for my QOTD tomorrow:
When you have shot and killed a man you have in some measure clarified your attitude toward him. You have given a definite answer to a definite problem. For better or worse you have acted decisively.
In a way, the next move is up to him.
R. A. Lafferty
To talk about "proportionality" in a national self defense context is foolish. If a country binds itself to a "proportional" response, it gives its enemies control over their own punishment. "If we don't X them, they won't X us. So until we can absorb X, we won't use X".
The proper outlook for our enemies to have is, "If we X them, they might XXXX us. Or maybe Y, we know they have Y in their arsenals. Z too. Allah knows what other letters those crazy Infidels have. Better not mess with them."
Proportionality is self defeating.