Thefts of U.S. technology boost China's weaponry

China's government also uses influence operations designed to advance pro-Chinese policies in the United States and to prevent the U.S. government from taking tough action or adopting policies against Beijing's interests, FBI officials said.

Rudy Guerin, a senior FBI counterintelligence official in charge of China affairs, said the Chinese aggressively exploit their connections to U.S. corporations doing business in China.

"They go straight to the companies themselves," he said.

Many U.S. firms doing business in China, including such giants as Coca-Cola, Boeing and General Motors, use their lobbyists on behalf of Beijing.

"We see the Chinese going to these companies to ask them to lobby on their behalf on certain issues," Mr. Guerin said, "whether it's most-favored-nation trade status, [World Health Organization], Falun Gong or other matters."

The Chinese government also appeals directly to members of Congress and congressional staff.