Coastal surveillance

While most Chinese on the mainland regard US arms sales to Taiwan as an infringement on China's internal affairs, reminding them of the humiliation by Western powers in the century following the Opium War in the 1840s, many also are disturbed when they read about US air and naval surveillance off the Chinese coast.

What comes to mind for most Chinese is the shocking image of the Chinese PLA Air Force pilot Wang Wei whose plane collided with a US Navy EP-3 spy plane off the coast near China's Hainan Island, on April 1, 2001. Wang died in the accident, and the 24-crew members on the EP-3 made an emergency landing in Hainan.

The incidence sparked a nationwide protest in China against the US and China suspended all military contacts and exchanges with the US.

Over the years, Chinese leaders have repeatedly called on the US to stop its aerial and sea surveillance off China's coast. However, the US said it will continue the surveillance.

Guan, from the Ministry of Defense, said the increasing frequency and closer distance of US surveillance runs contrary to efforts of building mutual trust, calling it an "unnecessary Cold War action".

Citing the EP-3 incident as an example, he warned that such surveillance represents the highest possibility of leading to unintended conflict when military planes and ships encounter one another more often.

The two countries concluded a Military Maritime Consultative Agreement in 1998, which was supposed to help prevent and resolve such possible incidents.

Some Chinese scholars ask how the US would feel if Chinese military planes and ships started to conducting frequent patrol and surveillance off the US coast, such as near California, Florida or New York.

The US argued that it is legitimate and free to conduct surveillance in the Exclusive Economic Zone (EEZ) and it does so not just to China, but other nations in the world as well.

Glaser from the CSIS said countries have different interpretations of the United Nations Convention on the Law of the Sea and the kind of activities that can be conducted in a country's EEZ.

"The majority of countries agree with the US interpretations, but not all," she said.

Senior Colonel Zhou Bo from the Ministry of Defense, revealed at the Shangri-La Dialogue in Singapore in June that China had thought of reciprocating by sending ships and planes to the US EEZ and had done so a few times, in contrast to the frequent surveillance by the US in China's EEZ and near China's airspace.

Legal restrictions

Despite the increasing cooperation and exchanges between the two militaries, the US still imposes legal restrictions on military cooperation with China.

The US, which imposed sanctions on arms sales to China after 1989, is also pressing the European Union to keep its ban on arms sales to China.

That ban, which put China on a list with only a few countries, is also humiliating to Chinese.