If you abolish SS and Medicaid you would, of course, need to refund about $6 trillion to the people you took it from and which is as yet unspent. You can't just take that money and build highways and resthomes for illegal alien workers. You need to give it back. That'll run the national debt up over $21 Trillion.
Now, DOD, and this won't be popular ~ but DOD can exact tribute from client states. That's how it was done in the good old days. No reason we can't revise that custom.
The fact of the matter is the money has already been spent. You can't "give it back". It is gone. Whatever money there is in the future will be earned by future private sector workers and investors.