To consolidate military and aid resources, we should plant our flag on a couple more continents. Sure the age of colonialism ended about 100 years ago but consider the savings. If We absorbed the failed state of Liberia, we could have a strong African presence without needing to deal with local dictators. We historically owe Liberia, but that is a different matter.
As for Asia, think Phillipines. They were a part of the USA for a long time. Having actual territory would reduce our need and expense to placate allies in these regions. Just a thought.