>>512521086 (OP)prisoner's dilemma
partly it's pride/face saving as
>>512521208 says but they're also trapped by legal machinery.
namely, the fact that you have to assert your rights as a nation with action under international law has hilarious consequences like those asian water cannon fights.
legally speaking, if a national leader doesn't do the correct retaliatory airstrikes then he's supposed to be replaced with one who will.