BEIJING - Pentagon officials said Tuesday that two US B-52 bombers have flown over the area of the Diaoyu Islands, which is included in China's newly established Air Defense Identification Zone in the East China Sea.

In response, a Chinese Defense Ministry spokesman said the Chinese military monitored the entire flight course of the US aircraft, which flew along the eastern border of the air zone, some 200 km east of the Diaoyu Islands.

The US move appears to be a cautious probe of China's ability to manage the airspace, but it risks escalating tensions in the region.

Washington has been overreacting to the establishment of the zone with groundless accusations.

It is known to all that the United States was among the first to set up an air defense zone in 1950, and Japan followed suit in the 1960s. There is no reason to blame China for doing the same.

Since the Diaoyu Islands are an inherent part of Chinese territory, Beijing is fully justified under international law to have the air defense zone cover the islets.

While accusing China of attempting to change the status quo in the East China Sea, US Secretary of State John Kerry seemed to forget that Japan fired the first shot with the provocative move to "purchase" and "nationalize" the Diaoyu Islands last year. China is simply forced to take countermeasures to defend its legitimate rights.

Washington has repeatedly said that it takes no position in the territorial dispute between China and Japan over the Diaoyu Islands, yet its acts belie its words.

The US overreaction has bolstered Japan intentionally or unintentionally, and obviously runs counter to its commitment to remaining neutral and its call for restraint by relevant parties.

If Washington continues to say one thing and do another, it may send wrong signals and lead to miscalculation, which will be detrimental to peace and stability in the already sensitive region.

It is advisable for the sole superpower in the world to act as an honest broker to make contributions to regional peace and stability.