No, politicians are very (street) smart. Science produces results in the long-term, but elections are every x years and a career is maybe y years, all of which are shorter than the time in which science will show definitive results. So politicians will just look out for themselves as much as they can. The reason militaries get funded is because it plays on the basest fear in people and the money makes it back into politicians' pockets fast without having to show any more results than a pile of rubble.

You're right however, that nowadays it's structural that scientists request funding through defense, like of course it needs that cover.