I don't give 2fucks if anyone joins or not the Navy, military or [Insert abc glowie agency here]. Also people don't join the military because of politics, they join for both a sense of service and need i.e work/education because 99% of the people in the military even at the officer level are from really poor shitty backgrounds and have no choice.
Believe me I think the Navy is a shitty choice and I'm glad I'm out in 6 months.
If you want to stop supporting Israel I would first look at the reason why people join in the first place, i.e they have no other option because American culture does fuck all to help people unless there's a monetary gain from it.
If you go down to Yokosuka which is like 45min from Tokyo station by train on the Keikyu line. It's basically an American Colony for all intensive purposes. Also none and I mean NONE of your anime, cosplay, hentai, goth lolita, weeb culture would exist if it were not for America not only after the war but before it in the late 1800's with Commodore Perry's expedition to Japan.
The country would be a backwards 3rd world shit hole divided by colonial powers or if WWII didnt turn out with us in Japan, something far worse than North Korea and Hunger games combined when the soviets inevitably moved in.
The very fact there are statues of Gen. McArthur built voluntarily by the Japanese is proof just how much the country is intertwined with America.\