A sailor is taking part in the fire drill on the Chinese patrol vessel "Haixun 01" on April 8, 2016 in the South China Sea. [Photo/Xinhua]

The Pentagon has once again pointed accusing fingers at China, this time for what it claims was an "unsafe" intercept of one of its spy planes by two Chinese fighters over the South China Sea on Tuesday. But as a Chinese proverb observes, the offender complains first.

The US has again defended its innocence by stressing the spy plane was flying in international airspace. But this was contradicted by the Chinese Ministry of National Defense, which said it was "extremely close surveillance of China by US military aircraft."

Because the two militaries have agreed upon a code of conduct to control risks and to deal with unplanned encounters at sea and in the air, the event will probably end up as just another footnote in the history of the perennial cat-and-mouse game on China's doorstep.

But we should not mistake the wood for the trees. The crux of the problem lies in the massive, intensive and close reconnaissance activities the US conducts against China. They not only constitute military provocations, but also threaten China's sovereignty and territorial integrity.

Reports indicate the US conducts more than 1,000 spying missions close to China's borders each year, more than the annual number of spying missions it conducted against the Soviet Union during the Cold War.

Yet it insists it is the wronged party and that it has no intentions of trying to contain a rising China.

US saber rattling in the South China Sea has intensified in recent years, particularly after Washington announced its "rebalancing to the Asia-Pacific". And its top naval commander in the Asia-Pacific, Harry B. Harris, has called for an even more confrontational approach to China in the region.

Thanks to its military and economic supremacy, the US has assumed the role of rule-setter worldwide. Yet it simply ignores those rules when it suits its purpose. Thus it deems its spying missions on China's doorstep are perfectly acceptable, while China's measures to safeguard its national security are slammed as "unsafe", "unprofessional" or even "dangerous".

While more communication is needed between the two militaries to ensure that their militaries' air and sea encounters are safe, the safest bet for regional peace and stability is the US reduces, minimizes and finally ends its flagrant spying on China.

To peep into other's courtyard uninvited is at best impolite; to criticize the host for objecting to such behavior compounds the injury.