In defiance of Beijing’s controversial decision to declare an Air Defense Identification Zone (ADIZ) last week, U.S. B-52 aircraft flew over the disputed Diaoyu/ Senkaku islands in the East China Sea. China’s Defense Ministry has given a relatively muted response to the flyover, much to the dissatisfaction of China’s vocal netizens.

China’s ADIZ includes several disputed areas, but the cluster of islands known as the Diaoyu to the Chinese and Senkaku to the Japanese has been a point of conflict between China, Japan and Japan's ally, the U.S. According to China’s rules on the ADIZ, all aircraft planning on flying in the area are required to provide flight plans, clearly mark their nationality, and maintain two-way radio communication with Chinese authorities in order to avoid a potential confrontation due to “defensive emergency measures” by the Chinese military. Refusing to comply with Beijing’s newly demarcated air defense zone, U.S. military aircraft kept conducting operations in the area without submitting flight plans or being in radio communication with China, sending a clear message that Washington was willing to push back. On Tuesday, two unarmed B-52 bombers from the U.S. airbase on Guam island flew in the ADIZ.

“The Chinese military monitored the entire process, carried out identification in a timely manner, and ascertained the type of U.S. aircraft,” China’s defense spokesman, Geng Yansheng, said in a statement. “China is capable of exercising effective control over this airspace,” Geng added. The foreign minister also responded to the flyover, saying the Chinese response to flights in the airspace would depend on “how big the threat was.” The diplomatic response to the flyover was not exactly what some Chinese netizens had expected.

“If the air defense zone is just a temporary, spoken thing, without means to handle other countries provocatively entering without permission, then we’d be better off not setting it up, because it’s completely unnecessary,” one commenter based in the southwestern Chinese city of Chongqing wrote on Weibo. “Is that response what they meant by ‘emergency’ reaction? Seems kind of weak,” another blogger chimed in.

“That’s it?” other users responded.

Meanwhile, the New York Times is reporting that Ni Fangliu, a prominent Chinese historian and journalist, posted on his Weibo account China “will face international ridicule” if the military fails to respond to an aircraft entering the air defense zone.

While the subdued response from China’s authorities may have surprised Chinese netizens, there was a flood of support over the initial ADIZ announcement. Much of the conversation online was approval for the newly established ADIZ, which many believed was set up over an area rightfully belonging to China. “Claiming what is ours and now defending what is ours,” one blogger wrote. “This is something that is worth fighting for,” another added.