That restraint may finally be wearing thin after the release of the Mandiant report and the public acknowledgment of its accuracy by security experts, DoD officials, intelligence analysts and U.S. lawmakers, said Anup Ghosh, CEO and founder of security firm Invincea.
Since the report was released, "the pressure has been mounting on the [Obama] Administration to not only acknowledge the threat, but also to declare how they will defend U.S. interests against the Chinese cyber threat," Ghosh said.
"The acknowledgement by the Pentagon is a first step in publicly declaring the threat," he said. "The administration still needs to lay out what steps it will take to both defend against the threat as well as discourage unrestrained attacks against U.S. interests."
According to the Pentagon, China's cyber espionage activities are allowing the country to collect data for intelligence and network attack purposes.
The cyber attacks are also designed to slow down incident response times and disrupt logistics, communications and commercial activities, the report warned.
The report offers little information on capabilities of other countries to launch cyber attcks on U.S. interests.
In the past, security analysts and even the government have noted that China is by no means the only nation focused on ramping up its online spying capabilities.
The U.S. is also no laggard in launching cyber attacks on other nations.
For instance the Stuxnet attacks that disabled centrifuges at Iran's nuclear facilities in Natanz in 2010 are believed to have been carried out by security experts in Israel and the United States.
A 2012 report from the U.S. Department of Defense's Defense Security Service (DSS) entities said East Asia, where China is located, and the Pacific region, accounted for 42 percent of all attempts to collect sensitive U.S. data illegally. That report considered a range of espionage activities, and not just cyber espionage.
The report said the Near East, comprised of Iran, Israel, Libya, Saudi Arabia and other countries, is the second most active region, with 18 percent of all reported cyber attacks. Europe accounted for about 15 percent of the attempted attacks since 2007, while South and Central Asian countries such as India, Pakistan and Bangladesh were said pose a moderate cyber threat over the next few years.
John Pescatore, director of emerging security trends at the SANS Institute, said that while there's little doubt that China is actively engaged in cyber intelligence collection activities, the U.S and its allies are as well.
He noted that China's focus is on stealing industrial and trade secrets to close gaps in its own capabilities. That focus compares to the Soviet Union's effort to steal U.S trade secrets during the cold war.
Pesactore previously worked for the U.S. National Security Agency (NSA).
Traditionally, the U.S hasn't had to widely engage in industrial espionage because its capabilities have been well ahead of countries like China. Instead, its intelligence gathering efforts have been focused more on defense and security related goals, and more recently, counter-terrorism objectives, Pescatore said.
Jaikumar Vijayan covers data security and privacy issues, financial services security and e-voting for Computerworld. Follow Jaikumar on Twitter at @jaivijayan, or subscribe to Jaikumar's RSS feed . His e-mail address is firstname.lastname@example.org.
Read more about cyber warfare in Computerworld's Cyberwarfare Topic Center.