I hadn't thought of it this way, but Krugman makes the point in today's op-ed, and it's a good one:
And what about the growing military crisis? The mess in Iraq has placed our volunteer military, a magnificent but fragile institution, under immense strain. National Guard and Reserve members find themselves effectively drafted as full-time soldiers. More than 40,000 soldiers whose enlistment terms have expired have been kept from leaving under "stop loss" orders. This can't go on for four more years.(As Krugman has frequently said, "Things that can't go on, don't.")
This graf is not the major thrust of Krugman's piece. And I know there have been lots of threads on the draft returning (draft boards being filled etc). But it's worth dwelling on the implications of what he's saying.
If you're preventing "volunteers" from leaving when their hitches are up, you already have a draft. It's not a prediction, it's a fact. You haven't extended it to the wider population yet, but the pressures to do so are there and growing.
on edit: forgot Mr Krugman's
LINK.