Known unknowns and known knowns
It's almost hilarious to see the pantomime of Rumsfeld going "out of his way to say he still did not know with any certainty if North Korea possessed a working, deliverable nuclear weapon or not." So we have a country telling the US to its face that it has a nuclear weapons capability and the most hawkish of hawks is treating this as (in his own nomenclature) a known unknown, whereas only a couple of short years ago we had the massed ranks of the Bush administration declaring that Saddam Hussein's supposed imminent possession of a nuclear capability was a known known and using this as a pretext for war. As Bush put it in his 2003 State of the Union address:
The International Atomic Energy Agency confirmed in the 1990s that Saddam Hussein had an advanced nuclear weapons development program, had a design for a nuclear weapon and was working on five different methods of enriching uranium for a bomb.
The British government has learned that Saddam Hussein recently sought significant quantities of uranium from Africa.
Our intelligence sources tell us that he has attempted to purchase high-strength aluminum tubes suitable for nuclear weapons production.
Apparently, according to the now fully-discredited Iraqi defector Khidir Hamza, speaking in August 2002, Saddam would have had nuclear weapons by now (2005). Obviously this all turned out to be 24 carat horseshit.
The only conclusion to draw from Rummy's current attitude can be that the US doesn't particularly want a war with North Korea at the moment as it thinks that Iran looks like a much tastier target (if only things would quieten down a bit in Iraq). But what exactly the US administration's plan for North Korea is, is still a mystery, as it has been for the last four years.
Lest we all get too excited about North Korea's self-declaration of nuclear manhood, Jeffrey St. Clair has a good article on the current nuclear ambitions of the US. Apparently most of its stockpile of 10,000 nuclear warheads are too old and potentially 'unhealthy' and they need to build a new generation of bigger and better nukes. Meanwhile, the tactical mini-nukes and 'nuclear earth penetrators' may have suffered a bit of a setback but Rumsfeld is finding ways to bring their development back online.
I'll leave you with a small gem I found while browsing Bush's 2003 State of the Union (if we ignore Condi it's just about perfect):
Throughout the 20th century, small groups of men seized control of great nations, built armies and arsenals, and set out to dominate the weak and intimidate the world.