@Walter Hinteler,
I was thinking. If that's true of American Jews, would that also apply to others such as the Japanese for Japan. I don't think so.
When the US was attacked by Japan on December 7, 1941, Japanese Americans were also killed at Pearl Harbor.
However, there were first generation Japanese on US soil who rooted for Japan to win the war. Even then, those same parents told their second generation Americans to remain loyal to the US. Most of us know what the Japanese Americans accomplished during WWII.
I think as a culture, we are proud of our heritage. Japanese in the US and in Japan have accomplished much. With the assistance of the US after WWII, Japan became a economic super power. What is amazing is that Japan has almost no raw material of her own, and yet developed an economy that is second to none for its size.
Japanese scientists have won many Nobel prizes, and recently was awarded for developing LED lighting. Their cars are popular all around the world, and win safety and quality awards frequently.
I think there may be some differences about the pros and cons of supporting ones cultural home land.