That would be a problem with the allocation of funds by the government itself. A standard tactic to blackmail taxpayers into getting gouged. The answer is that the government has total discretion of how to allocate the funds, and if 0 isn't cutting where he should the problem is with 0, not the amount budgeted. But the numbers still say that the military (and this isn't counting veterans benefits) got a 55% budget increase over ten years with a concomitant 3.8% increase in active duty personnel
At least you got the problem being with “0” right. He wants to cut the military to fund his social welfare programs. Defense is in the constitution, social welfare programs are not.