I would say sub- 5% given a low prior for rich, well-governed nations fighting all out wars, Japan being relatively demilitarized still (and war being technically illegal), and the US having a defense commitment there.
Japan being relatively demilitarized still
On paper, sure. In practice the JSDF is one of the world's top ten military forces by overall measures.
As Multiheaded added, "Personal is Political" stuff like gender relations, etc also may belong here.