Plenty of people have been scratching their heads over Joe Biden’s warning to voters that electing Barack Obama would precipitate an international crisis to “test his mettle”. Investors Business Daily agrees with Biden, and notes that this wasn’t an off-the-cuff gaffe; Biden repeated the warning in two different venues. IBD points to this early Obama campaign video, in which Obama pledges unilateral disarmament on several fronts, as evidence supporting Biden’s hypothesis:

But there’s another angle to this, based on what Biden the senator knows — that Obama’s defense policies, once it’s obvious how they’ll undermine us, are likely to be very, very unpopular. In this case, Biden may be calling on his party’s hard, pacifist core — Moveon.org, Code Pink and the like — to stand by their man.

He’ll need their support. Like Jimmy Carter in the 1970s, Obama’s policies often sound good on the surface, but will in fact materially weaken America’s ability to defend herself. That’s not just our opinion, mind you; it’s straight from the horse’s mouth. …

Such policies will create a vacuum that our foes will be only too happy to exploit.

In response to seeing a weakling in the White House, will Russia do something rash in Eastern Europe, like invade Ukraine? Will South Korea develop a bomb, knowing the U.S. won’t stop it? Will Iran attack Israel, as it has promised, thinking America has become a paper tiger? We don’t know, but maybe Joe Biden does.

Indeed. This video had been largely forgotten since its appearance early in the primaries, when Obama sought the support of the Kucinich Left in his party. Obama deliberately positioned himself to the left of Hillary Clinton in the hopes that he could wrest support from people like Dennis Kucinich and Chris Dodd and emerge as the alternative to the Restoration. Only after he beat Hillary in the primaries did he move back towards the center on issues like the FISA reform bill, long after he had locked up enough support to gain the nomination.

Since then, though, Obama has tried hard to position himself as a Scoop Jackson Democrat. He has dropped all mention of the missile defense system or of unilaterally cutting back nuclear weapons. Obama worked hard over the summer to project himself as a traditional strong-defense candidate, and it seemed to have worked … until Biden inadvertently undermined him this week. It eliminated any help the Colin Powell endorsement gave him in terms of national security, and gave John McCain and Sarah Palin a gift on the campaign trail in reopening the national-security issue.

But did Biden mean to warn that unilateral disarmament would be unpopular, or that Obama would initially alienate the Left by demonstrating military strength in an international crisis? One could argue it either way, but I don’t think he meant to worry about the Left leaving Obama. I think Biden wanted the Left to remain activist to support a retreat philosophy in the face of aggression from our enemies. Obama has consistently fronted that policy, in Iraq and elsewhere, both as a Senator and as a presidential candidate.

Biden knows Obama will need the Left to support the consequences of its Kucinich vision for American foreign policy. That’s what the warning meant, and this video is ample evidence of the direction Obama will take in national security.