The feds have painted themselves into a corner with all their "protections":

I think it is likely that by 2030, the discretionary portions of the budget will disappear. This means that politics will be all sound and fury, signifying almost nothing. It will be about who is appointed to the Supreme Court. It will have to do with issues of free speech and rights of non-cooperation. It will be all hat and no cattle.

By the time the Democrats can get back into the White House in 2022, it will be too late for the incoming President to have any effect on federal spending. Yet politics is all about special-interest groups getting their hands into the federal till. Political promises are made to these special-interest groups, but the absence of discretionary components in the federal debt will prevent almost all of these promises from being fulfilled. For all intents and purposes, national politics will be decided in terms of debates over social issues that have no budgetary consequences. All the rest of politics will simply be political rhetoric: sound and fury, signifying nothing.

The welfare state works only as long as the government can get its hands on other people's money. There are serious limits politically on the ability of the federal government collect taxes from the public. That limit is about 20% of GNP. The increase in nondiscretionary spending in the federal budget is going to place the welfare state in a straitjacket. This is good news in general. There is no way that America can grow its way out of the straitjacket. But the straitjacket is limited by the enforcement of federal laws, and without money for enforcement, Americans are going to get out of the federal straitjacket. I won't live long enough to see it, but maybe you will.

He explores the subject in more detail here. While I agree with the general framing, I disagree on the outcome. In general, the army gets stiffed last according to my reading of history. I don't see any reason to believe otherwise, personally -- they'll just print money when they run out of discretionary spending.