His grandfather was big in Japan during the war. In Japanese terms, Abe was very much a part of the permanent governing elite.
Practically everyone in Japan’s rulers is descended from one of the samurai families that have been running Japan since the mid 1800s. Abe was one of the better ones, able to balance Japan’s interests while working with all big dog countries.
Japan’s governing elite is quite different from ours. They actually have the interests of their own people at heart.