I think we could build nations, but we simply don’t have the STOMACH for it, and even if our leaders did, they’d be jailed in Europe for taking the necessary steps (such as torturing and then killing leftists/terrorists and their families, taking down entire towns and cities that ‘resist’, etc.).
So, it’s not really money, but it doesn’t matter - you’re right, we can no longer do it.
It’s un-American that we should be a nation running around the world torturing and murdering in the name of nation building. There simply is no need for us to do that inn order for us to build a nice life here. We aren’t the third reich.