According to David Sanger in the NYT, some folks in the Administration are thinking very carefully about the intelligence problem in interdiction:
Pentagon officials are clearly not eager to confront the Kang Nam 1. The intelligence about what is on board is typically murky. Some say they suspect small arms, which are banned by the United Nations resolution but hardly a major threat. Members of Mr. Obama’s team who served in the Clinton administration remember past embarrassments, including the interception of a Chinese ship suspected of carrying chemical precursors in the early 1990s. When the ship was finally cornered, the cargo turned out to be benign.
That’s the Yinhe incident, for those of you keeping score at home.