It's not hard to imagine a scenario in which mankind is so desperate for survival that collective efforts are abandoned in favor of self-preservation of each nation state. Some marginalized country, fearing they will lose out under a UN-led effort to "equitably" distribute the seed stockpile, sends their military to take control of the vault in order to ensure their own survival. (There is also a future Bond movie here: Evil mastermind takes possession of humanity's only remaining source of sustenance for leverage in the pursuit of [pick one] financial gain/destruction of ethnic group/world domination.)

The Norwegians are aware enough of the importance of preserving plant biodiversity to spend millions to construct the seed vault. Are they aware enough to ensure an appropriate security plan for the stockpile? Apparently not. The vault will not be permanently manned. Instead the intention is for the vault to be guarded by the polar bears that "patrol" the mountains. Yes, that's right - I said polar bears. And why not? I mean, the polar bear has become the poster child of global warming - a species certifiably doomed to extinction with the melting of polar icecaps - why shouldn't he make a buck off of his impending demise and live it up while he can? No? Come on, it's possible. The polar bear - only animal known to actively hunt humans, lethal by both land and sea. I'm sure he'd make a fine protector... No, not convinced? Me neither. Pitting polar bears against possible security threats, I'd put my money on a small army, secret agent, or, you know, pretty much anyone with a gun. A roving band of wily snowcats? Sure, the polar bears have it. An armed militia? Not so much.

The point is, under any imagined seed stockpile security breach, it's going to take more than polar bears to protect the vault. But the hibernation-prone defensive force isn't the only flaw in the vault's security plan. The Norwegians seem intent on giving away the seed reserve to future agroterrorists. The vault is located on the Svalbard archipelago. The placement of the vault on a remote island makes the structure sea-accessible and thus more vulnerable to invasion. And while you'd think that at least the vault would be hard to locate in the desolate, snow-covered landscape, the Norwegians even found a way to work around that. The structure includes a publicly-commissioned sculpture (Norway requires one percent of public building budgets to be set aside for artwork). The "large, sparkling metallic sculpture" will be placed next to the vault's entrance and is designed to be visible for miles around, essentially serving as a beacon to rogue nations and secret agents in search of the stockpile. At this rate, Norway may as well establish a bird sanctuary on the island and cast open the doors to the vault.

Conclusion: we should invade Norway and take their oil (they are the world's third largest exporter of crude oil). What kind of an army can these people possibly have? If the Norwegians' plan for safeguarding the future of mankind is through the deployment of vicious polar bears, I'm pretty sure we can take them out by the end of the week.

UPDATE Feb 2008
United Nations applauds the seed vault.

AUTHOR'S NOTE
I have only met one Norwegian, the husband of my colleague. He is a lovely man, and I wish him and his people no harm. As for the polar bear, lest you question my compassion for their predicament, please know that my best friend growing up was a three foot polar bear named Cuddles who I took with me everywhere I went.