China's blistering attacks on U.S. tech firms is more than quid pro quo over cyberspying charges. It's a signal of China's growing confidence in its own technology capabilities.

China makes its own computer chips, has the world's fastest supercomputer

"Foreign tech firms pose threat on Internet." It'srattling Microsoft with TV spots that threaten to ban Windows 8. Chinese server maker Inspur is running an "IBM to Inspur" initiative, which according to reports, might seem like a spin from an old Sun vs. IBM server battle.

But this isn't just about cyberspying. China is picking and choosing its targets carefully.

Here are five reasons China is acting the way it is now.

1. China is asserting itself

China President Xi Jinping, a chemical engineer by training, is clearly wielding power. He took office last year.

Six months after taking office, Jinping approved an air defense identification zone in the East China Sea, requiring aircraft to report flight plans, and provide other information. It is also exercising territorial rights for drilling in the South China Sea, antagonizing Vietnam in particular.

China's military capabilities are rising. It now has an aircraft carrier, and gave Chuck Hagel, the U.S. defense chief, a tour of it in April. China is working on stealth aircraft, and made that clear in a slide presented at a conference showing how its high performance computing (HPC) systems are used in its military aircraft development operations.

Andrew Bartels, an analyst at Forrester, sees China's recent posture on U.S. tech companies as part of its overall approach. China "Has become more assertive of its position in foreign policy," he said.

2. China's innovation policy pushes U.S. tech to the side

China wants to wean itself from as much foreign tech as possible. Its plan is to reduce its dependency on foreign technology from about 50% today to 30% by 2020, according to a report released last last year by the Congressional Research Service.

There's much hostility about China's indigenous innovation program in Washington because of how it operates.

Foreign firms are under pressure to transfer technology in exchange for access to China's market. U.S. Sen. Ron Wyden (D-Oregon) called the process a "shakedown" at a hearing in May.

China, in its attacks, is not targeting databases or other business systems.

It's going after hardware and information services, because that's where it is making the most progress.

3. China's hardware capability is increasing

China's most obvious display of tech innovation is in its development of HPC systems. It is now building systems made entirely of indigenously developed products, including chips and interconnects.