U Well, actually, you can. A lot of countries do it. It's probably not sustainable long term, but you can use it to grow for a while and then change when it becomes untenable. If you produce more internally and it's all consumed internally, you'be still grown. Most developed countries have run a spending deficit for the vast majority of the past century. The UK has barely ever run a surplus in living memory. The trick is to grow your economy (or inflate your currency) faster than the debt piles up. You're somewhat right in that if you do pile the debt too high it'll come tumbling down, but we're not there yet and our debt:GDP even now after years of heavy deficits aren't far removed from comparable countries.