Here's the problem - there's usually a stipulation of good faith. A Chinaman investing money in your company with the intent to clone it like that is not in good faith, and would be so adjudicated by any American court of competent jurisdiction. Even if, however, your contract is technically enforceable in American court, it's not easy to go get some one from China to punish.

In America, you're very much expected to be a "right guy" when dealing with others. Regardless of what the piece of paper says, you will (deservedly) gain a bad reputation is you exhibit bad behavior, and become a person with whom no one wishes to transact. Word will get around. I think this system of doing things is highly effective, contracts aside. Interestingly enough, this is strongest in the South, followed by the Midwest, and only occurs to a lesser degree on the coasts. I sill haven't figured out why.

China has a very different perspective. Her business culture involves things like committing embarrassing acts in each other's company, a sort of mutually assured destruction. For better or for worse, when these two cultures mix, American businessmen end up the suckers.