On the Feburary 12, North Korea agreed to finish the following within 60 days, which is April 14:
1) Shut down and seal for the purposes of eventual abandonment the Yongbyon nuclear facility; 2) Invite back the IAEA to conduct all necessary monitoring and verifications;
3) Discuss with the other parties a list of all its nuclear programs, including plutonium extracted from used fuel rods, that would be abandoned pursuant to the Joint Statement.
But now after receiving its 25 million dollars and 50,000 tons of heavy fuel oil, it didn't fulfill its commitments. Inside the Bush administration, hawks are attacking pigeons' policy. On the negotiation table China, Japan and South Korea asked the US to be patient. However, if the other parties fail to persuade North Korea fulfill its commitment, the US role in the six-party talk and policy on the issue will have a 180-degree change. I don't mean that there will be a war, but that there will be stalemate.
As the frozen money was released, the US doesn't have much leverage. The leverages to push Kim Jong-il are now owned by China and South Korea. However, as I see it, even for the latter parties, the effectiveness is limited. North Korea now has everything it needs to survive this year. It recently received its money, energy and 400,000 tons of food from South Korea. Kim Jong-il can guarantee the society not to get worse in the near future and the safty of its regime. If he needs aid, what he needs to do is to resume the dialogue or make some "promises". Secondly, Kim Jong-il perceives that it will be safe for him to test the bottom line. Becasue of the issues in the Middle East and the North Korea nuclear test, the US has been softening its stand point on the table; China opposes regime change in North Korea due to the concern of potential refugee wave; South Korea will continue offering food aid and oppose violent change for the relations with North Korean brothers.
I think North Korea's strategy is to linger as long as possible. The advantages are: it can keep on its nuclear and missile programs and wait for more advanced weapons; it can keep regime stable and gain by making advantage of the softness of the US policy and the unwillingness of China and South Korea to exert violent internevtion; it can wait for the leader change and policy change in 2008 US presidential election (Based on the current situation, it will be unlikely that US domestic politics will agree on another war). Thus, I think there won't be material progress in the rest of 2007. The turning point may be when North Korea need more aid and when the new US president is elected.