Self-defence is available to individuals to communities and to nations. It is ethically and legally sound to engage in self-defence.
The principle of proportionality should be applied when engaging in self-defence. This means that you should do no more advertently, than is necessary to remove the threat. For example, if somebody begins punching you on the nose you are justified in punching back until your adversary is incapable of punching you again. You would not be justified in deliberately killing your adversary. However, if your adversary vowed to begin punching you at every opportunity until you were dead, you would be justified in killing or permanently disabling your adversary, if there was no other way to prevent such attacks on your person.
If, having repelled an attack on your person by an adversary intent on your death, such adversary asked for time-out to recover in order to resume the attack, you would be justified in not granting the time-out.
I hope this is all clear. Joe Biden, Antony Blinken, Anthony Albanese, and Penny Wong should take note. So far as I know, the Allies didn’t pause their push into Germany and suspend fighting to allow humanitarian aid to reach German civilian populations. They suspected, no doubt, that the Wehrmacht might take the opportunity to regroup.