Russian and Chinese warships entered what Japan called the "contiguous zones" near the Diaoyu Islands almost at the same time on Wednesday night.

Speculation has grown in Japan whether this meant China and Russia were joining hands to send a signal to the US-Japan alliance. Tokyo launched a solemn protest to the Chinese Ambassador to Japan, but downplayed the Russian warships' move in order not to escalate the situation, giving only a "notification."

It will be a nightmare for Japan if Chinese and Russian navy and air forces join hands in the West Pacific.

The US is still going against historical currents and trying to solidify its global military alliances. Japan is one of its most active allies.

China and Russia both face pressure from the US. There is a motive for them to become allies. But the leaders of the two countries have not done so. China and Russia have done their part to make sure the world does not fall into serious division and confrontation.

Why is Japan so nervous about the appearance of Chinese and Russian warships near the Diaoyu Islands? It is simply because Japan harbors something that cannot bear daylight. The US-Japan alliance has been showing a growing power to damage peace in the Asia-Pacific region. It is impossible that the outside world does not respond to their provocative actions.

China and Russia are sticking to their flexible Comprehensive Strategic Partnership. But in global issues, the two have been enhancing their cooperation. Their joint military exercises have become more frequent. The closer relationship has resulted from Western pressures. China and Russia both know that if either of them is crushed strategically, it will disadvantage both.

The US, Japan and the rest of the West often talk about China and Russia "growing closer." Such sensitivity results from their own attempts to forge allies. They are aware of their unjust squeezing of China and Russia's space and are worried that China and Russia may join hands to counteract.

China and Russia have greater space for further cooperation. How close they will be depends on whether the US, Japan and the West as a whole will further cross the lines.

The US and Japan should restrain themselves if they do not want to see closer Sino-Russian cooperation in the West Pacific. The US should not seek a military advantage that seriously threatens China and Russia. Japan should not be too high-profile in its allying with the US.

Japan is afraid of both the US and Russia, because both countries have defeated it in the past.

Toyko's different reactions to China and Russia's warships near the Diaoyu Islands are ridiculous. It only tells the world how they should deal with Japan.