Despite Beijing's bluster and hints of another break in military exchanges, little fallout is expected from Washington's decision to upgrade Taiwan's F-16 fighter jets.
A move to sell the island new fighters would have stirred a more vociferous response, but Washington deferred that the decision. The announcement also comes at a time when both sides are seeking stability in ties ahead of U.S. elections and a looming leadership transition in Beijing.
"China's reaction is relatively moderate compared to previous years, which was what people had in fact been expecting," said Yu Tiejun, an Asian security expert at Peking University.
"China-U.S. relations are in a very subtle period. So China's reaction needs to be rational," Yu said.
China's Foreign Ministry condemned the sale as undermining overall ties and military exchanges, and Vice Minister Zhang Zhijun summoned U.S. Ambassador Gary Locke in Beijing to complain. The Defense Ministry warned it had "created severe obstacles for the normal military-to-military exchanges of the two countries" and called in Washington's military attache to Beijing.
The strong words are seen as merely rhetoric catering to the military and nationalistic public who regard the U.S. as an interloper that uses support for Taiwan as a means of restraining China's rise. China reacts strongly to all U.S. military cooperation with the island, but previous threats to sternly retaliate have yielded no long-term damage to relations, despite occasional freeze on military exchanges and postponement of meetings.
"For the sake of legitimacy, the regime has to respond strongly. There will always be bluster and threats bandied about, but they also know that the U.S. is their most important foreign relationship," said Gabe Collins, a Michigan-based expert on the Chinese military.
"At the end of the day, I don't think there'll be significant damage," said Collins, the co-founder of China Signpost, an online publication that follows China's armed forces.
China regards the democratic island of 23 million people as part of its territory, and sees the arms sales as undermining China's efforts to woo back Taiwan. The two sides split amid civil war in 1949.
The $5.85 billion upgrade will provide new radars, weapons systems, pilot training, spare parts and structural upgrades, but is not nearly as advanced as the electronics, avionics and fire systems aboard the C/D models that Taiwan had long wanted to purchase.
In Taipei, Taiwan's Foreign Ministry hailed the Obama administration for "responding to our request proactively by taking concrete actions to approve" the upgrade. In a statement late Wednesday night, the ministry said the package is "composed of many advanced systems."
Beijing temporarily suspended military exchanges with the U.S. last year after the Obama administration notified Congress it was making $6.4 billion in weapons available to Taiwan, including missiles, Black Hawk helicopters, information distribution systems and two Osprey Class Mine Hunting Ships.
Military exchanges are again considered the most likely target of China's wrath, although Beijing could also cancel some symbolic meetings. Even then, the impact would likely be slight _ China has long viewed defense contacts as a political bargaining chip and they have yielded little amid frequent interruptions.
How much anger China makes evident would depend on how much pressure there is from the public and influential military officers who often give speeches and write newspaper editorials.
"It's hard to say what specific actions China will take about this issue because it depends on too many things," said Wang Dong, a Peking University U.S. relations expert.
Along with the need for overall stability in its political ties with the U.S., China also needs to keep trade and investment steady and maintain access to U.S. high technology for projects such as its future passenger jet that would compete with Boeing and Airbus.
In addition, China is preparing to send vice president and assumed future leader Xi Jinping to Washington this year for a major profile-building visit. A significant rise in tensions could poison the atmosphere for such a trip, tarnishing Xi's image as future leader of the world's most populous nation and second-largest economy.
Taiwan's appeals for U.S. military assistance are driven largely by China's rapid military modernization, especially in its air fleet. Over recent years, the People's Liberation Army Air Force has added scores of advanced Russian Su-27 and domestically developed J-10 warplanes to its fleet, and recently began testing a prototype stealth fighter called the J-20. China is also sea testing its first aircraft carrier, a refurbished Soviet model bought from Ukraine.
Taiwan, meanwhile, has seen its air defense edge degraded as its fleet of F-16 A/Bs, French Mirage 2000-5 and domestically developed IDF fighters steadily ages.