The currently popular idea of "setting precedent" is overrated, misused and an argument, and shouldn't be taken as "it will definitely happen all the time soon"

The currently popular idea of "setting precedent" is overrated, misused and an argument, and shouldn't be taken as "it will definitely happen all the time soon". The Japanese "set precedent" by bombing Pearl Harbour. How many seaports of the US have been bombed by a foreign power since then? The US dropped two nukes on Japan. Did it "set precedent" for nations to nuke each other willy-nilly in wars since then?