— Imposes a high cost of entry: American companies are forced to turn over key technology, just to enter the market. They describe it as a kind of pay-to-play — in the world's second-largest economy.

— Then matchmaking: In some key industries, like China's energy, telecom and auto sectors, U.S. companies have to form joint ventures with domestic firms. That means transferring valuable technology — intellectual property — to the local company, allowing then local firms to create their own new products in their own new technology.

Cybersecurity rules rolled out by China in the past couple of years? They've only added to those concerns. For instance, when companies have to share valuable source code or possibly be excluded from a billion potential customers, it's a Catch-22.

But American tech companies aren't turning away from China for one basic business reason. They can't. The market is just too big to ignore.

There are 1.4 billion people in China — more than quadruple the population of the United States — all of them with some buying power. Plus, China is booming compared to other large nations. It's accounted for as much as 43 percent of the world's projected tech growth in recent years.

So while the possible payoff is high for innovators, so is the cost for their home country. One estimate says the U.S. loses as much as $600 billion a year to intellectual property theft. And China is considered a major "infringer."

China's response to international concerns? It's simple. The premier said last year, "We will fully implement our plan for developing strategic emerging industries."