North Korea reacted angrily to tougher sanctions after its third nuclear test . After the United Nations slapped tougher sanctions on North Korea after its third nuclear test in February this year , Pyongyang screamed in defiance . North Korean trade with China has been a lifeline for the isolated regime . But Beijing has struggled to control the angry rhetoric from its neighbor . Expert : North Korea fears a Chinese collapse would spark a refugee crisis .
North Korea reacted angrily to tougher sanctions after its third nuclear test . North Korean trade with China has been a lifeline for the isolated regime . But Beijing has struggled to control the angry rhetoric from its neighbor . Expert : North Korea fears a Chinese collapse would spark a refugee crisis .