Wikileaks on Sunday released hundreds of thousands of U.S. State Department documents online and to news organizations, presenting a range of potentially embarrassing revelations about back channel diplomacy between the U.S., allies, and other countries.

The documents, not all of which were immediately accessible to the public due to the cyber attack on Wikileaks, reveal discussions on a range of sensitive matters around the world, including worries about nuclear proliferation in Iran and North Korea.

The cables also reveal that China's Politburo "directed the intrusion into Google's computer systems," according to the New York Times, which was provided with copies of the documents.

A Chinese contact reportedly confirmed to U.S. embassy officials in Beijing the involvement of China's government in the cyber attack on Google's network that occurred late last year and was disclosed in January, 2010. The officially sanctioned cyber attack involved government operatives, private security contractors, and Internet criminals recruited by the Chinese government, the New York Times said.

Security companies said as much back in January. A report issued by iDefense, a computer security company owned by Verisign, claimed that 33 other companies were targeted in the cyber attack and that those responsible were working either directly for, or on behalf of, official intelligence entities of the People's Republic of China.

Such claims however have always proven problematic because finding the IP address of a computer through which an attack was conducted doesn't definitively reveal who controlled that computer or directed those responsible. And indeed, Chinese officials have repeatedly denied any involvement in the attack on Google and other companies.

Google declined to comment.

In a press briefing on Nov. 24, Philip J. Crowley, Assistant Secretary of Public Affairs at the State Department, said the cables are classified and denounced Wikileaks' decision to release of the documents.

"We decry what has happened," said Crowley. "These revelations are harmful to the United States and our interests. They are going to create tension in our relationships between our diplomats and our friends around the world. We wish that this would not happen. But we are, obviously, prepared for the possibility that it will."

U.S. Secretary of State Hillary Clinton has reportedly been reaching out to leaders in various countries to prepare them for the release of the diplomatic cables.