Why is China Not Using His Strength to End the N Korea Nuclear Issue?

If China really wanted to help solve the nuclear arms issues of N. Korea, there is no reason that they couldn't play hardball with North Korea and get them to stop testing nuclear weapons. However, some speculate that China has not bothered to confront North Korea under such harsh terms because they realize it is a thorn in the side of the United States military and it keeps us busy.
It would be unfortunate if China hasn't put forth their effort because they like to see the United States of America spend lots of money dealing with the North Korea problem. If China is trying to get the United States bogged down in Asia, then one has to ask why the United States of America has the Chinese as their number one trading partner.
After all our trade deficit with China is hundreds of billions of dollars per year. There is no way that the Chinese could have experienced 10% year-over-year growth in that nation without the help of all of the imports that we buy from them. Ever since the US consumer has stopped buying China's exports are down by between 35-50% depending on the sector.
Many of the large international shipping companies have cargo containers stacked up in US ports, and they have taken ships out of their lines. If China is going to take advantage of their trading status with the United States in this way, then perhaps, the US consumer might consider boycotting Chinese goods. If this were to happen China's economy will not recover from the global economic recession.
Some say we can't do that because China is floating our debt in the US. While this is true, if China does not buy our treasury notes, maybe our Congress will stop spending so much money, which in reality would be good for America. Some ask if China is a friend or foe; and while it is true that China does what's best for China and not necessarily for any other nation, one could obviously see that that China is not an ally of the United States, merely a trading partner.
In this case we should treat them as a trading partner, and not an ally and kick their 6000 spies out of our nation, and clamp down on poisonous dog food, baby food, and toothpaste. In fact, anything coming from China that does not meet our standards, well we ought to have those ships completely turned around and sail back home to their mainland.
At some point China needs to understand that we are a Western civilization and we operate on a win-win scenario. Until China understands that, we need a timeout in our trade.