Apparently you don't understand how pensions work. Take a 401(k). Under normal circumstances what you take out of the 401(k) far exceeds what you put into it. This is what happens with investments generally speaking.

Saying, "Social Security beneficiaries receive more than they paid in..." indicates you don't know what you are talking about. And, believe it or not, Social Security does invest money.

And yes, it does salvage the argument. Defense spending (all of it not just DOD) is the largest expense of the government. This is expected when you are the hegemon.