elmer fudd: “When the existence of your country and your people are on the line you don’t play by Marquis of Queensbury rules.”
War is not simply about destroying the enemy. War is about achieving your nation’s objectives at least cost. If playing by Marquis of Queensbury rules achieves those objectives, you play by the rules.
And that implies that there is an effective, fair referee & ringside judges.
Barring that, wipe them out as quickly and cheaply to self as possible, unless they unconditionally surrender.
A war IS about destroying one's ememy, unless one is engaged in an AGRESSIVE war; NOT a defensive war. When attacked, all rules & bets are off.