General David Petraeus, the top US commander in Iraq, is widely viewed as the architect behind a “surge” of 21,500 troops. But even Petraeus believes that the Bush Administration’s policy is unlikely to succeed.

Oregon Senator Gordon Smith said Friday that Petraeus told him privately that “we have a one in four chance that Bush’s plan will work.” (Thanks to Josh Marshall for unearthing Smith’s remark.)

The Administration and its loyalists are constantly urging critics of the war to give Petraeus time for his policy to bear fruit. But is it tactically smart–and morally justifiable–to send 21,500 more troops into a mission that even our top generals believe is likely to fail?

And how in the world does the Administration still not have a backup plan. “Plan B was to make Plan A work,” Tennessee Governor Phil Bredesen recalled after a group of governors met with the White House last week.

Or maybe there’s a plan C: Topple Iran and hope nobody remembers Iraq (or Afghanistan).