Former U.S. State Department translator Tong Kim makes a few “pertinent observations”:http://www.koreatimes.co.kr/www/news/opinon/2009/04/167_42603.html about the recent decline in U.S. access to North Korea, and how it relates to Pyongyang’s special way of doing things:

Beginning January, several groups of private Americans with a varying degree of expertise on North Korea ― including Stephen Bosworth prior to his appointment as the top North Korea policy coordinator ― visited Pyongyang and told the North Koreans about their views of what’s coming from the new administration vis-a-vis North Korea. Their message was the new administration would be serious to resolve the issues of mutual concern bilaterally with Pyongyang and multilaterally through the existing six-party talks.

The North Koreans turned down Ambassador Bosworth’s plan to visit Pyongyang, which was part of his initial consultations with the participants in the multilateral talks for denuclearization. Bosworth’s Asia trip immediately followed Secretary Hillary Clinton’s visit to the region, during which she had sent mixed signals to Pyongyang. Although the North did not publicly react to some of the secretary’s displeasing remarks, the North Koreans did not find a clear departure from the Bush Administration’s policy other than a shift in approach ― with the appointment of a senior envoy and giving more weight to direct diplomacy.

Conversely, the North stepped up provocative threats on South Korea and imposed new demands that the United States should treat it as a nuclear weapons state and that it should first normalize its relationship with the DPRK before denuclearization. The North also lowered the level of its interlocutors for most of the American visitors, from vice foreign minister to the director-general of U.S. affairs ― from Kim Gye-gwan to Li Geun.

An aside: Bosworth recently “hinted at this shift”:http://www.totalwonkerr.net/1947/batman-begins. We continue with Tong Kim:

bq. It is also notable that Pyongyang denied a recent American visitor group access to the Yongbyon nuclear complex: the group included Siegfried Hecker, a well-known nuclear authority, who had visited the site five times before. Hecker’s first visit was allowed because the North wanted to prove its nuclear capability, which was eventually demonstrated by a nuclear test.

Another aside: Prior to the release of the operating records and the start of disablement operations, “SIGINT”:http://www.totalwonkerr.net/1866/just-a-little-bit-more-information (as in, you know, “Sig” Hecker) was the primary form of transparency at Yongbyon after the collapse of the Agreed Framework.

Tong Kim:

bq. The denial of access does not indicate possible renewed nuclear activity. But the North may want the world to speculate on what is or what is not going on there. Pyongyang knows how to play the cutoff of information to the outside world or the effect of ambiguity to its advantage.

That seems about right.