MEGAN MCARDLE:

People who aren’t worried about setting up a big new entitlement, because after all, we’re going to have to fix it eventually, are encouraged to read Paul Blustein’s excellent book on the Argentinian crisis, And the Money Kept Rolling In (And Out). Unsustainable fiscal policies can end when the government tightens its belt and raises taxes and cuts spending–or it can end when the whole thing melts down spectacularly. . . . At best, when we do start cutting back, we will make various people who planned their lives around current government policy substantially worse off. That’s something that we should be thinking carefully about, not blithely endorsing.

Indeed.