North Korea and China remain as close as lips and teeth

Last May, Kim Jong Il visited China again to ask for continued economic and military aid and political support. As urgent a mission was introducing his heir apparent, Kim Jong Un, to the Chinese senior leaders.

As North Korea's major ally, experts say, China's support for the young Kim was important.

China-North Korean ties are so close they are frequently described "as close as lips and teeth," and the two neighbors were Korean War allies. Of all the regional powers, Beijing has the greatest potential leverage over Pyongyang. China supplies at least 80% of North Korea's oil and significant amounts of food, fertilizer and military aid. The two Communist neighbors have frequent political, military and party-to-party exchanges.

Former CNN correspondent, Mike Chinoy, a veteran Korea-watcher who has visited North Korea several times, said: "The Chinese have made it extremely clear that they are not going to let Korea go down the drain. They are going to do whatever they need to do to prop it up."

Foremost in Beijing's mind, North Korea serves as a buffer, keeping the U.S. troops stationed in South Korea away from the Chinese border.

Meantime, experts say, all eyes are on the young and untested Kim Jong Un. Chinoy, now a senior fellow at the Los Angeles-based U.S. China Institute, notes the young Kim's big challenge: "How does somebody who's not yet 30 win the loyalty and respect and command authority over the entrenched party apparatus, the entrenched military bureaucracy, and the senior party officials who may have been in their positions for a long time?"

Kim Jong Un has only had two years to ascend as a senior party leader and four-star general. He is expected to rely on powerful backers of close relatives, including Kim Jong Il's sister and brother-in-law Jang Song Taek, who experts say will serve as regents, tutoring behind the scene.

Most Korea-watchers do not expect North Korea to implode immediately, nor is any huge policy change expected.