Contrary to the opinions of some, Kim Jong-un ordered the hit and is in complete control of the DPRK. No one would have dared to kill a Kim family member without specific orders from the very top.
North Korea is willing to poison relations with the few countries with which it has reasonably close relations. Up until the assassination, Malaysia allowed North Koreans to enter without a visa, but now visas are required. The DPRK may have thought it could bully Malaysia into surrendering Kim Jong-nam's body without conducting an autopsy. The method of killing, VX nerve agent, "is the most potent of all nerve agents." The DPRK was lucky in that no one else died. Or too ruthless to care.
Much of the media noted that China stopped coal exports, with coal being the DPRK's largest export by volume, but they misses the larger issue. China is no doubt annoyed because it "had played host to and protected the half brother of the North Korean leader for many years."
But China has used North Korea as a buffer zone against the West since 1949. It has always desired to push its borders further out, most notably in the South China Sea. It has no intentions of causing an implosion which would force it to deal with millions of refugees streaming in from the DPRK, and even worse from its point of view, possibly see U.S. troops north of the DMZ for the first time since 1953. It prevents Western reporters from learning the truth about China, even going so far as to make them sign confessions.
And now North Korea has suspended the export of rare earth minerals to China in a tit for tat for the suspension of coal shipments. This is a much bigger story than the media appreciates, given how much of the world's clean energy, magnets, high-tech weapons, and other modern technology is dependent upon rare earth minerals. It wasn't that long ago that China implemented a rare earth minerals export slowdown. Officially, China is responsible for 97% of the world's rare earth mineral exports, but an unknown percentage of that actually comes from North Korea.
China currently supplies North Korea with most of its oil, as well as food and electricity. The coal and rare earth mineral embargos will end soon, with the former being political theater for China to present to the world.
"Even though none of the minerals -- copper concentration and zinc concentration from Hyesan mine, Tungsten from Daebong mine, and molybdenum from Yonghwa mine -- are being exported, Hyesan mine is still using electricity from China," a source in Yanggang province told RFA. "This implies that the export suspension won't last long."
If Kim Jong-un is willing to murder his own brother in a most painful manner and poison relations with one of the few quasi-friends it has in the world, we can assume he would be willing to throw the dice in other venues.
Kim Jong-il was asked by his father, Kim Il-sung, the founder of the DPRK, of the possibility of a loss by the North Korean military. The generals refused to answer because they knew it might be a death sentence to admit that the DPRK could lose in battle. Kim Jong-il eagerly shouted out: "Great Leader! I will be sure to destroy the Earth! What good is this Earth without North Korea?"
Kim Il-sung smiled and said: "That is surely the answer. I am pleased to see that a new North Korean general has been born at this very gathering. Henceforth, I transfer to you the operational command of the North Korean military."
Kim Jong-un is definitely his father's son.