Historically, it is minuscule. It wasn’t too long ago that waging a war for too long would bankrupt most countries, but the US has been waging wars for almost the entire time it’s existed, and it’s managed to build the worlds largest economy while doing it. But you’re suggesting we debate whether defence spending should be 3 percent rather than 4 of GDP. If all of our allies properly contributed to our defence, it could probably be 2 or less. I’m not a big supporter of government spending, but the effectiveness of our defence spending for its tiny relative cost is remarkable compared to literally any other period in history.