By fighting imperialist ideas and people pushing them. By fighting for a rules-based world order. Right now the best defense of the "indutrial-military complex" is that it is necessary, which is sadly true. If you don't like it, remove its reasons to be necessary.
I recommmend analyzing the strategies of the so-called New Left during the 1960s-70s. Their ability to disrupt the status-quo and bring attention to the State's death machine can't be understated. For a starting point - check out the direct action tactics used by the Weather Underground.