North Korea swings between provocation and negotiation . Comment: China -- which committed as many three million troops to secure North Korea during the Korean War in the 1950s -- is Pyongyang 's closest ally but has grown increasingly impatient with its Stalinist neighbor , repeatedly urging it to rejoin the six-party negotiations . The U.S. insists de-nuclearization is a pre-condition of talks . Analysts say North Korea 's behavior is now an embarrassment to China .
North Korea swings between provocation and negotiation . Comment: The U.S. insists de-nuclearization is a pre-condition of talks . Analysts say North Korea 's behavior is now an embarrassment to China .