Neville chaimberlin
There are two issues, 1 is decency so if there would be a need for soldiers in America to protect Americans then it doesn’t make sense that the goyim should have to protect us and we shouldn’t chip in. If it doesn’t fit with our lifestyle then we would not be able to live here in good conscience. BH we aren’t needed for America’s protection.
2) in Eretz Yisroel there is a Mitzvah and a chiyuv to help defend the Yidden and the land. It doesn’t say anywhere that Frum people or lomdei Torah aren’t obligated to participate in this Mitzvah.
The only reason that Frum people don’t want to participate is the lifestyle of the secular Israeli army and that can be changed if there is a will on both sides. Obviously this last paragraph does not pertain to those who hold like Satmar although I’m not sure why since defending Yidden shouldn’t be tied in with gimel shavuos.