As terrible as each of those things were, his point largely stands. Most things labeled 'terrorism' are better handled by police/. Obviously the stupidly large mountain of money the US gov spends on 'defense' didn't save people from those. A country's defense budget is really for defending itself from invasion, and our risk of that is low. The last meaningful example anyone can give is pearl harbor - which was 80 years ago in a pre nuclear world.
You don't need to spend more than most of the rest of the planet on the military to defend an area of land that's a tiny proportion of the world's surface. Are you sure you've been paying attention to US foreign policy over the last hundred years?