Close all U. S. military bases on non-U. S. soil or territories, position returning troops on international borders, reduce the military budget(s) appropriately. This removes the U. S. presence from countries that do not want U. S. in their country, stops illegal crossing of the U. S. national borders, provides employment for U. S. troops rather than "dumping" those individuals on the civilian economy, seals the national borders to help in resisting attacks on U. S. soil.
Additionally, if a similar agreement can be reached with Canada, the U. S. national borders with Canada need not have "boots on the ground".