On Wednesday, wire services reported that a senior Chinese official charged foreign intelligence services of causing “massive and shocking” damage to his country through computer espionage.

A vice minister of the Information Industry, Lou Qinjian, did not identify any culprit by name, but he did state that 80% of the computers used in the attacks were based in America. Beijing’s accusation came suspiciously only after months of reports of Chinese hacking into Western government information systems.

President Bush had been expected to raise the issue with his Chinese counterpart, Hu Jintao, during their 90-minute meeting in Sydney last Thursday. The two leaders had time to discuss a wide range of topics, including China’s role in Sudan and Iran. They even found a few moments for a friendly chat about next summer’s Olympics.

Mr. Bush, however, was not anxious to talk about the recent Chinese hacker attacks against U.S. government networks. The Pentagon suspects that China’s People’s Liberation Army successfully penetrated an unclassified computer system serving the office of Defense Secretary Gates this June.

The system was shut down after the perpetrators had obtained information, some of it sensitive. The Pentagon attack followed ones last year in July on the Commerce Department’s Bureau of Industry and Security, in November on the Naval War College, and in December on the National Defense University. In the spring of last year, China accessed State Department computers and installed backdoors in networks to siphon off information on China and North Korea.

Since 2003, when the Chinese attacks against American targets began, there have been hacking attempts on the Army Information Systems Engineering Command at Fort Huachuca, the Defense Information Systems Agency in Arlington, the Naval Ocean Systems Center in San Diego, and the Army Space and Strategic Defense Command in Huntsville. America has codenamed China’s systematic efforts “Titan Rain.”

Moreover, Chinese hackers have probed Britain’s House of Commons and Foreign Office. They may also have tried to penetrate the Ministry of Defense.

In May, Germany’s domestic intelligence service discovered that the Chinese had attacked the German chancellor’s office and at least three ministries, infecting their systems with Trojan spyware.

Japan is a frequent target, especially since Microsoft surrendered its source code to Chinese civilian authorities as part of a commercial deal worked out in 2002. This week a French defense official confirmed reports that Chinese hackers had infiltrated his country’s systems.

Beijing has not yet contradicted France’s claim, but it has denied it was behind any of the other incidents, labeling accusations “groundless,” “irresponsible,” or “a reflection of Cold War mentality.”

China announced that it had set up cyber warfare units in early 2003. As the Heritage Foundation’s John Tkacik points out, they are the only parts of China’s military “that regularly attack enemy targets in the course of their duties.” And they are extraordinarily good at it.

Many of the recent attacks have been traced to China’s southern Guangdong province and the northern cities of Beijing and Lanzhou. The hackers are sophisticated and extremely proficient, being able to get in and out without keystroke errors and leaving little or no evidence of their breakins. They possess expensive software, and their methods smack of military organization.

Internet use in China is tightly regulated. Hackers could not have gotten out through the country’s great firewall or received data from foreign nations without Beijing’s participation in their efforts. The perpetrators were looking for information that is only valuable to the Chinese military and the Beijing government. No one could have operated such a large hacking organization without the knowledge and participation of the authorities.

China’s military has openly discussed employing cyber attacks to defeat more powerful adversaries. There is only one conclusion that fits the facts — the People’s Liberation Army is behind the recent spate of computer hacking incidents.

So what is the West doing about them? The chancellor of Germany, Angela Merkel, confronted the Chinese premier, Wen Jiabao, at the end of last month during her trip to Beijing. But what about Mr. Bush, the most powerful individual in the world? The American leader did not say one word about the attacks against our nation’s critical networks.

Instead, Mr. Bush talked about establishing a military hotline with China. “Hotlines have had a long history of basically serving as confidence-building measures,” Deputy National Security Adviser Jim Jeffrey, who accompanied the president to Australia, said. “I wouldn’t say it will relieve tension, because right now we don’t have tension in the military sphere.”

If there is no tension right now between Washington and Beijing, it is only because Mr. Bush cannot bring himself to confront the truth about aggressive Chinese behavior. And why should we be trying to build confidence with China while the People’s Liberation Army is conducting a series of coordinated attacks against us and our allies?

Moreover, we don’t need a hotline to tell the Chinese to stop the cyber attacks. It would be better for everyone if we start having public conversations with Beijing about these malicious attacks. After all, Chinese hackers pose at least as much a risk to our national security as, say, Islamic fanatics — and certainly more risk than Sudanese militiamen or Iranian theocrats. If Ms. Merkel can complain about China’s hostile acts and the Chinese are able to make wild charges, why can’t Mr. Bush say something on this serious threat?

Mr. Chang blogs at commentarymagazine.com and is the author of “The Coming Collapse of China.”