Just Emes, that’s a nice theory, but it was never made as a frum state. It was, from the beginning, founded and run by kofrim, for the propose of kefirah, and still is. Whether the sholosh shavuos applies to a frum state is not relevant to the state which was formed and now exists.
I still agree with your initial statement that we owe hakaras hatov to individuals who defend Jewish lives, including IDF soldiers. But the idea of kashering a state founded on the notion of Am Yisrael disconnected from the Torah, ch’v, is awful, because that notion is kefirah.