Kissinger was correct when he said that the Korean War symbolized "China’s determination to end its 'century of humiliation' and ‘stand up’ on the world stage." You can see this manifested in the comments on articles in The Diplomat from Chinese nationals. Some of them are downright foaming at the mouth against the U.S. for China's treatment over the years, though one would have guessed that Chinese anger would be greatest against the British.
Kissinger is also correct that "China and the United States have taken parallel positions in the UN Security Council demanding that North Korea abandon – not curtail – its nuclear program," because their rationales are entirely different. The U.S. wants to eliminate a mad dog with ever-growing teeth, while China does not appreciate the DPRK's upsetting the status quo of maintaining North Korea as a buffer zone against the West.
China is somewhat like Russia in this respect. Russia has become unhinged due to NATO creeping ever closer to its gate, even though there was never any written promise by NATO to refrain from doing so. That said, China's attempt at controlling the South China Sea is much worse than Russia's attempt at creating Новороссия, (new Russia) using Crimea, southern and eastern Ukraine, and Transdniester, because it is aggression aimed at many countries which never had anything to do with China.
But then Kissinger returned to his usual self with this statement: "In 1979, China changed course and, under Deng Xiaoping, proclaimed a nonideological foreign policy." In truth, Kissinger and Tricky Dick got snookered by Mao and Deng. Deng was much craftier and more foresighted than the West knows. He realized how he could leverage the bluster and unfettered capitalism of the U.S. to make China a great power. The proof is the vast amount of trade the West has with China, when there was never any significant trade with the USSR.
Bosco opined that the proof for the DPRK's increased aggression is the "sinking of the Cheonan and shelling of Yeonpyeong Island," but he seems to have forgotten about the 1976 DMZ ax murder incident, the 1987 bombing of KAL 858 which resulted in 115 deaths, and many other provocations which occurred before Kim Jong-un became Kim 3.0.
The police state of North Korea has remained pretty much the same the same since Kim Il-sung first created the DPRK in 1945 with the able assistance of the Soviet Union.