Mark Ralston / AFP - Getty Images

A Chinese paramilitary officer rides a scooter in Beijing on Wednesday. Beijing dismissed an annual Pentagon report that accused it of widespread cyberspying on the U.S. government, rejecting it as an "irresponsible

BEIJING -- China on Wednesday accused the United States of sowing discord between it and its neighbors after the Pentagon said Beijing is using espionage to fuel its military modernization, branding Washington the "real hacking empire.”

The latest salvo came a day after China's foreign ministry dismissed as groundless a Pentagon report that accused China for the first time of trying to break into U.S. defense computer networks.

The Pentagon also cited progress in Beijing's effort to develop advanced-technology stealth aircraft and to build an aircraft carrier fleet to project power further offshore.

The People's Liberation Army Daily called the report a "gross interference in China's internal affairs.”

"Promoting the ‘China military threat theory’ can sow discord between China and other countries, especially its relationship with its neighboring countries, to contain China and profit from it," the newspaper said in a commentary that was carried on China's Defense Ministry website.

The United States is "trumpeting China's military threat to promote its domestic interests groups and arms dealers,” the newspaper said, adding that it expects "U.S. arms manufacturers are gearing up to start counting their money.”

The remarks in the newspaper underscore the escalating mistrust between China and the United States over hacking, now a top point of contention between Washington and Beijing.

A U.S. computer security company, Mandiant, said in February a secretive Chinese military unit was likely behind a series of hacking attacks that targeted the United States and stole data from more than 100 companies.

That set off a war of words between Washington and Beijing.

China has said repeatedly that it does not condone hacking and is the victim of hacking attacks -- most of which it says come from the United States.

"As we all know, the United States is the real 'hacking empire' and has an extensive espionage network," the People's Daily, a newspaper regarded as a mouthpiece of the Chinese Communist Party, said in a commentary.

"In recent years, the United States has continued to strengthen its network tools for political subversion against other countries,” the article said.

"Cyber weapons are more frightening than nuclear weapons," the People's Daily said. "To establish military hegemony on the Internet by repeatedly smearing other countries is a dangerous and wrong path to take and will ultimately end up in shooting themselves in the foot."

Related links:

Report: China snooping around Pentagon computers

'Not based in fact': China angrily denies being behind widespread US hacking

Analysis: As cyberthreat looms, here's what really matters

Carlos Barria / Reuters

A Chinese People's Liberation Army soldier stands guard in front of 'Unit 61398,' a secretive Chinese military unit on the outskirts of Shanghai, on Tuesday. The unit is believed to be behind a series of hacking attacks, a U.S. computer security company said, prompting a strong denial by China and accusations that it was in fact the victim of U.S. hacking.

BEIJING -- China's military on Wednesday responded angrily to accusations by an American computer security company of systematic hacking of U.S. business and military interests, arguing it "lacked technical proof and was "not based on fact."

In a statement published on the Chinese Defense Ministry's website in response to the controversial report by Mandiant Corp., the military denied the charges, arguing the data was not enough to connect the hacking to them.

"The report, in only relying on linking IP address to reach a conclusion the hacking attacks originated from China, lacks technical proof," the ministry wrote in its statement, "Everyone knows that the use of usurped IP addresses to carry out hacking attacks happens on an almost daily basis."

The ministry also argued that there was no globally accepted definition of what constitutes hacking.

"There is still no internationally clear, unified definition of what consists of a 'hacking attack'. There is no legal evidence behind the report subjectively inducing that the everyday gathering of online (information) is online spying."

The Defense Ministry said that China itself is a frequent victim of hacking, a common theme in China's rebuttal of accusations of foul play in cyberspace. The ministry said it had tracked a "considerable number" of attacks against its networks that originated in the United States, but it noted that those intrusions had not been used "as a pretext to accuse the U.S. side [of hacking]."

The statement came a day after Mandiant released an explosive report, first detailed in a New York Times article, that tied a People's Liberation Army unit based in Shanghai to a prolonged and focused campaign of stealing corporate and defense trade secrets.

According to Mandiant, the Chinese hacking unit, believed to be "PLA Unit 61398," employed hundreds, perhaps even thousands, of operatives to raid secure American servers, extracting trade secrets, blueprints, pricing data and other valuable information.

In total, Unit 61398 was said to have pillaged hundreds of terabytes of information from 141 companies -- 115 of which were American -- representing 20 industries in a variety of fields including telecommunications and defense.

The hackers reportedly used techniques such as "spear-phishing" -- using spoof e-mails to trick users into granting access to internal servers -- demonstrating a strong proficiency in English and advanced understanding of computer security and network operations.

China pointed out that its Ministry of Public Security had assisted more than 50 countries and regions in investigating cybercrime cases and that the Beijing had entered into a number of bilateral law enforcement cooperation agreements with those countries to help combat hacking.

The Mandiant report and the media maelstrom around it prompted Chinese state media to lash out at the hacking accusations, though the Chinese-language version of the New York Times story was still blocked in China.

China's typically nationalistic newspaper, Global Times, said Beijing should be more vocal in exposing hacking attacks conducted against China.

"Some officials have been punished for internally reporting that government websites have been hacked and secrets leaked, but almost no details have come out," the paper wrote.

"The Americans really know how to talk this (issue) up. All China can do is concede defeat."

Related: 

Report: Chinese army tied to widespread U.S. hacking

Congress urged to probe Chinese computer espionage

Jason Lee / Reuters

Visitors use toy weapons to shoot pictures of Japanese soldiers at a theme park in Wuxiang, Shanxi province, China, on Oct. 20.

Visitors at two Chinese theme parks can participate in performances (complete with actors and professional sound and lighting effects) where they can role play as soldiers from the Japanese army or the Chinese Eighth Route Army, one of the main military forces of the Communist Party during the Second Sino-Japanese War. The parks, located near the former headquarters of the Eighth Route Army, cost the local Wuxiang government around $80 million to construct.

Tensions between China and Japan have escalated in recent months over disputed islands in the East China Sea and anti-Japanese sentiment is on the rise in China. 

Jason Lee / Reuters

A woman dressed as a Japanese soldier runs along a trench during a live-action role-playing game at a theme park in China.

Jason Lee / Reuters

A boy dressed as a Japanese soldier pretends to shoot.

Jason Lee / Reuters

Actors dressed as Japanese soldiers pretend to shoot a man dressed as a plainclothes Eighth Route Army soldier during a performance at the Eighth Route Army Culture Park in Wuxiang, Shanxi province, on Oct. 20.

Jason Lee / Reuters

Actors dressed as Japanese military soldiers and Chinese villagers perform during a show at the Eighth Route Army Culture Park.

Jason Lee / Reuters

Pictures of Japanese military soldiers are displayed as targets for shooting at a theme park in Wuxiang, Shanxi province, China, on Oct. 20.

Also on PhotoBlog: 

• Taiwan boats enter waters disputed by Japan and China
• Communist ideals still strong in China's Nanjie village
• In China, super flowers rise above Tiananmen Square ahead of National Congress

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By NBC News’ Ed Flanagan

BEIJING – “We notice that the United States engaged in the joint military exercises with countries like Vietnam and the Philippines. We Chinese people treat this as interference in China’s relationship with neighboring countries and I think this is not conducive to security and stability in Asia, so I’m wondering how you would comment on this?”

And with that opening gauntlet, so began a 45-minute grilling of America’s top military officer, U.S. Chairman of the Joint Chiefs of Staff Adm. Mike Mullen.

Mullen, who is leading a 39-member* delegation on a four-day tour of China, stopped at Beijing’s Renmin University Sunday to talk with 150 students hand-picked by college officials.

The stakes were high for the admiral, as his visit represents the first high-level military visit to China by a U.S. military official since Secretary of Defense Robert Gates came in January. The trip follows what has been considered a successful visit in May to the United States by Admiral Mullen’s Chinese counterpart in the People’s Liberation Army (PLA), Chief of the General Staff Chen Bingde.

The students’ questions – likely screened in advance of the Q&A – were a veritable roll call of recent and long-standing grievances the Chinese have had with the United States: continued arms sales to Taiwan, presumed meddling in the South China Sea, China’s military development and the ongoing U.S. embargo on military weapons sales to the mainland, cyber warfare and the negative stance some U.S. politicians have taken toward China.   

It was perhaps no surprise then when it came out that those issues were the primary topics of discussion in high-level talks between Adm. Mullen and Chen Bingde on Monday.

For his part, Mullen gamely walked a fine line with the students. Facing the unenviable task of reaffirming American engagement in the region at a time when China is consolidating its own power here, he quickly followed up statements declaring America’s commitment to Asia with others that trumpeted China’s rise to the world stage.

“Now, more than ever, the U.S. is a Pacific nation. It is clear that our military interests and economic well-being are tied to Asia,” said Mullen before later adding, “The U.S. wants a positive, cooperative and comprehensive relationship with China.”

Mullen continued by saying, “China today is a different country than it was 10 years ago, and it certainly will continue to change over the next 10 years… It is no longer a rising power. It has, in fact, arrived as a world power."

Mullen was cordial and respectful throughout his talk, but he did not back down from what have become almost regular calls by American defense officials for greater transparency within the People’s Liberation Army.

"With greater military power must come greater responsibility, greater cooperation, and just as important, greater transparency," Mullen said before warning, "without these things, the expansion of military power in your region, rather than making it more secure and stable, could have the opposite effect."

Officially, China’s defense budget for 2011 is said to be around $93 billion, a 12.7 percent increase over 2010. Many military expects though believe that this number is vastly underreported.

Change in tone noticeable
If the questions themselves were not unexpected, the tone with which the questions were asked were noticeably more direct than in previous similar town hall style meetings.

In 2009 when President Barack Obama held a town hall Q&A with students in Shanghai, a question on American weapons sales to Taiwan was posed to Mr. Obama:

“I come from Taiwan. Now I am doing business on the mainland. And due to improved cross-straits relations in recent years, my business in China is doing quite well. So when I heard the news that some people in America would like to propose – continue selling arms and weapons to Taiwan, I begin to get pretty worried. I worry that this may make our cross-straits relations suffer. So I would like to know if, Mr. President, are you supportive of improved cross-straits relations? And although this question is from a businessman, actually, it's a question of keen concern to all of us young Chinese students, so we'd really like to know your position on this question. Thank you.”

Compare that phrasing to a similar question posed by a foreign language student Sunday to Mullen:

“As we know, the United States keeps selling advanced weapons to Taiwan and I think this goes against the regional stability and security you were talking about. As we have noticed, some U.S. Congressmen have questioned the legitimacy of arms sales to Taiwan, so my question is when will the United States stop selling advanced weapons to Taiwan?”

The directness of the question drew applause and some giggles from the assembled students. Mullen gave a similar response to the one Obama gave in 2009: he reaffirmed the United States’ continued support of the one-China policy, but said that arms sales to Taiwan are permitted by U.S. law.

Mullen’s response in particular to charges that American congressmen have questioned the need for Taiwan arms sales appeared to resonate with students as well when he noted, “there are 535 members of my congress and often times there are that many views on a variety of subjects.”

Responsible regional partners
Throughout his trip to China so far, Mullen’s mantra has been that it is time for a major power like China to be a responsible partner in regional issues. In particular, the maintaining of free waterways for commerce, greater transparency within the People’s Liberation Army and the peaceful mediation of territorial issues like the Spratly Islands – a 1.3-million-square-mile patch of the Pacific Ocean claimed by China, Vietnam, the Philippines, Malaysia, Brunei and Taiwan – are clear sources of American concern.

However, these calls by the United States have been received with a perception that the U.S. may be “blaming” China for its role in recent diplomatic and military flare ups in the region. Furthermore, there is seeming frustration here that the United States appears intent on framing China’s new regional responsibilities rather than allowing China to define them for itself.

Once again, it would appear that the United States and China are at loggerheads on an issue with no immediate resolution in sight. Mullen’s visit gives hope though that while differences and suspicions remain, the two parties are at least willing again to meet and talk it out.

*Correction: This post incorrectly stated that Admiral Mullen's China delegation consisted of 39 members. The correct number was 22.

KUNMING, YUNNAN PROVINCE--Although military-to-military relations between China and the U.S. appear to be back on track, they've been frosty for almost two years after a U.S. arms deal with Taiwan, which Beijing considers part of China. 

But there is one realm where military cooperation has endured without hiccup for half a century.

"This is a way of preserving a symbol of friendship between our two countries," said Major Li Xin of the People's Liberation Army (PLA).

Major Li heads a special unit training China's furtive flyers in the Chengdu Military Region.

No, not the J-20.

It's another kind of stealth fighter.

"This is the last military pigeon unit left in all of the People’s Liberation Army,” said Major Li.

Yes, pigeons

The unit is stationed on a PLA base near Kunming, where there were once many more such units, all set up in 1957 as part of a contingency plan in case communications were cut off.

On the base, 600 "jun ge," or military pigeons, are trained to be couriers able to carry messages in case of an emergency or a natural disaster such as a quake knocks out cell phone signals or the Internet.

Adrienne Mong

Pigeon conscripts go through training every day.

Every day, the pigeons are put through their paces.

Well, almost all.

When they were released from the coop for a daily flyover, all but four of the birds took flight immediately.

The four delinquents opted to park themselves on a ledge of the building next door. 

“If those four pigeons are too lazy to train, they might be discharged from the army,” a PLA major deadpanned to the NBC News camera.

The birds can fly up to 60 miles an hour for long sustained periods, and the ones that make it past the initial tests are smart enough to dodge hawks. 

One pigeon, in fact, flew from Shanghai to Kunming—a distance of 1,336 miles—in roughly nine days.  That was back in 1982.  His body has been embalmed and sits in a display case.

Their natural homing instinct makes these birds perfect for their mission.  “The pigeons are prized for their ability to be trained, their pace, and their reliability,” said Major Li.

They’re also valued for their pedigree.

Adrienne Mong

Conscripts of the PLA's Special Military Pigeon Unit prepare for training.

A little help from an old ally

“These are American pigeons,” said Chen Wenguang, who founded the special military pigeon unit.  He remains, even at the spry age of 82, an avid pigeon aficionado who given any opportunity happily launches into a long discourse about the health and abilities of each pigeon breed.

The birds in the PLA unit are descended from a batch brought over from the U.S. by the Flying Tigers, a voluntary group that helped the Chinese fight the Japanese on China’s western front during World War Two.

The group was part of the Chinese Air Force and comprised mostly American pilots and ground crews; it was commanded by General Claire Lee Chennault, also an American.

The Flying Tigers was instrumental in ongoing efforts to defend the Burma Road, a critical supply route, in 1941.  Burma was eventually lost to the Japanese, and the Flying Tigers were disbanded in 1942.

Adrienne Mong

A memorial in Kunming honoring the Flying Tigers of World War Two.

The corps was reactivated within the U.S. 14^th Air Force, once again under the command of Gen. Chennault.  From 1942 to 1945, the Flying Tigers flew cargo for the Chinese across the Hump (the eastern end of the Himalayan Mountains nestled in the region of India, Burma, and China), which had more or less replaced the Burma Road as a supply route—one that was far more dangerous, especially without reliable charts, weather forecasts, or functioning radio instruments.

But it was a great success, bringing Chinese and American pilots and other military personnel together.

Our PLA hosts were ready to note this old alliance at every opportunity. 

“The real reason we keep these pigeons is they’re part of history,” said Col. Qing Nianlong, the commanding officer of the PLA communications garrison unit of Kunming.  

It’s rare that the PLA engages with foreign institutions, let alone foreign journalists.  But the invitation to visit their pigeon unit suggests there’s a growing awareness within the PLA of the potential upside to being media-friendly.

Now if we could just get up close and personal with that J-20.

Getty Images

BEIJING – After SARS derailed my planned summer study abroad in Beijing a few years back, I decided instead to study Mandarin at the Monterey Institute for International Studies, a short walk away from the U.S. military’s Defense Language Institute.

As their students tended to come down to our school to look for language partners, I frequently had the opportunity to see the Chinese textbooks they were working with.

They were nothing like this People Liberation Army’s English primer from around the same time period I stumbled across the other day.

Comprising over 40 learning capsules ranging from “Common Orders” to “Ordering Enemy to Surrender,” the lessons are mostly short articles and dialogues on relevant subjects translated sentence-by-sentence into Chinese characters.

Most of the subject matter is innocuous enough, dealing with everyday life in the military. However, some of the lessons provided a fascinating look at the PLA indoctrination process that goes on even in foreign language study.

A section on “Military Communication” included this tacit warning that mass media required regulation and control [Note: Your computer may require Chinese language support to read characters]:

780. The mass media are developing in a daunting speed.

大众传媒正以惊人的速度向前发展。

781. Newly developed computer and digital communication technologies enable any one to communication freely.

新研制的计算机和数字化通信技术能够使人们自由通信联络。

782. You cannot control their free communications in a traditional way.

In another lesson on “UN Peace-Keeping Operations,” the lesson takes a poke at American indolence in regards to payment of UN dues:

845. Peace-keeping operations most of the times are faced with the problems of insufficient funds.

维和行动一直面临着资金不足的问题。

846. It happens because a majority of the 182 UN members do not pay their dues. The largest defaulter has been the United States.

之所以如此，是因为182个联合国成员国中的大多数国家不缴纳联合国会费。拖欠联合国会费最多的国家是美国。

While a third module entitled “The Developing Strategy and Military Theories” reminded PLA soldiers of China’s position on missile defense:

513. We are against the systems of the TMD [Theater Missile Defense] and NMD [National Missile Defense].

我们反对美国的战区导弹防御系统和国家导弹防御系统。

514. We'd like to cooperate with the U.S. in other fields.

我们愿意与其在其它领域进行合作。

Sadly, the sections for “The Question of Taiwan” and “Space War” were unavailable.

Again, this material seems to date back to 2003, and it is likely that the English language program at the PLA has undergone dramatic changes over the last few years. It is nevertheless, an interesting peek at the past of one of the most mysterious militaries in the world.