North Korea...again

So North Korea is raising its battered and hungry sycophant head again. Why does China support North Korea? I have talked with Chinese nationals who believed the North Korean leadership to be dangerous and unpredictable.
South Korea has thousands of our US troops, and has had them there since before the Korean War. The Cold War lives on in Asia...the so-called Bamboo Curtain still exists. When North Korea fired the missile toward Hawaii, the US did not seem concerned...that was only because the US knew North Korea would not have enough Wal-Mart extension cords to reach Hawaii. So today, North Korea blew up a South Korean ship, killing several individuals from South Korea. Dictator Kim Jong Il really needs to wake up and notice that he's forcing his people to kill their more peaceful brothers and sisters in South Korea.
Nobody in their right mind wants to have a war with the United States...just like nobody in their right mind would want the PRC and the US to be at war with each other. China needs to take care of the situation...do something the US would do when we took out leaders that we put in charge, or gave power to...like in the Philippines, Cuba, Vietnam, Iran, and various enemies of the US all over the world, that we put into power. The World likes to forget that many of those enemies of peace were our errant step-children, so when we go into these countries to remove the threats, most of them were from our past, and in some way shape or form were supported by us.
I recently read a report...Hilary Clinton gave some kind of a speech today in which she stated the Chinese were our friends...historically speaking, the Chinese were supportive of the Clinton presidency. However, officially, China is not our ally. China has not been our ally since WWII, when we went there to stop the Japanese threat. Now, Japan is our ally, along with South Korea, and unofficially, Taiwan...a somewhat free country claimed to be an errant province of China by the PRC.
North Korea has been our enemy since before the Korean War. We have had US troops there, guarding the borders to maintain peace since that time. Our members of the military have lost their lives guarding those borders, but we have not been allowed to defend ourselves there in an effort to keep that area peaceful. It is a weird situation that we should not be in. Korea should be unified and the families reunited. Dictator Kim needs a psychotherapist and a long vacation in a little room with padding.