lake Why do jewish young men from USA/ UK go to do there military service in israel?

Firstly, Israel's a US/UK ally, so they're not fighting against their home countries. Secondly, Israel's partly a country, and partly a religious home. If the Vatican had an army, we'd probably have Catholics doing the same thing. And finally, how can someone choose to be an Israeli since birth? It's hard to control where your parents deliver you.there