Now here is a something that could have some real consequences for North Korea as the South Korean government has decided to join the Proliferation Security Initiative:

South Korea’s decision to fully participate in the Proliferation Security Initiative (PSI) highlights its own resolve to stand its ground against North Korea’s continued provocations and play a bigger role in global security.

It also represents a major policy U-turn, prompted by North Korea’s April 5 rocket launch and nuclear test on Monday, from several years of maintaining a tepid stance toward the U.S.-led campaign to interdict suspected cross-border proliferation activity.

“(Participation in the PSI) is a natural obligation for a mature country,” Foreign Minister Yu Myung-hwan told a parliamentary meeting to discuss the impact of the latest nuclear test. “It will help control North Korea’s development of dangerous material.”

Realistically, the PSI is one of the few remaining cards Seoul can play against Pyongyang, as all but one joint venture — the Kaesong industrial park — has been shut down since the inauguration of South Korea’s conservative Lee Myung-bak administration early last year.

The Lee government has suspended food and fertilizer assistance for the North. Seoul remains committed to keeping the Kaesong complex alive, as it has invested nearly US$700 million in the project.

South Korea’s role in the PSI is a politically and ideologically sensitive issue. The initiative, primarily aimed at interdicting suspected ships, is not directed at any nation in particular. But North Korea — notorious for exporting weapons of mass destruction and related materials — is widely viewed as a main target.

North Korea has repeatedly warned it would regard the South’s participation in the PSI as a declaration of war. That stance made Seoul’s former liberal governments reluctant to fully join the effort, opting instead to follow the so-called “sunshine policy” of engaging the communist neighbor.

South Korea’s previous administrations also worried about the possibility of armed conflict if any attempt were made to interdict a North Korean vessel, and limited their participation in the PSI to observing offshore drills.  [Yonhap]

Joining the PSI and actually enforcing it are two different things however.  It will be really interesting in the coming weeks to see if the South Korean government will order their naval assets to intercept and inspect North Korean ships.  If they begin to do this I would not be surprised if North Korea starts to arm the ships or do something else provocative against the South Koreans in response.