Two can play the same game. After Chinese nationalists from Hong Kong asserted sovereignty over what the Chinese call the Diaoyu Islands and the Japanese call Senkaku, it was the turn of Japanese nationalists to unfurl the flag.
Over 100 Japanese lawmakers and nationalists sailed to the islands, with nine more swimming to the islands; all were subsequently questioned by Japanese customs officials.
The action by the Japanese nationalists provoked Chinese protests in southern Guangzhou as well as an official protest from the Chinese Foreign Ministry to the Japanese ambassador to China. The Foreign Ministry demanded that Japan cease undermining China's territorial sovereignty.
On Friday the Japanese government supported 14 Chinese activists from Hong Kong on the grounds that their setting foot on the islands was not a serious violation of the law. This was really an attempt to dial down the crisis between the two countries as China had demanded their immediate repatriation. The government was unaware that Japanese nationalist groups were ready to retaliate and thus aggravate the crisis further.
The Japanese government is already under attack for failing to press China against provocations by private groups that are egged on by the Chinese government. The Japanese critics claim that China has used fishing boats as an opening wedge in territorial disputes and then escalated to patrol vessels and warships to protect the Chinese fishermen. Therefore, acts by Chinese individuals should have been treated more severely. Chinese assertiveness, claim the critics,, is backed by a maritime buildup particularly in terms of patrol vessels and Japan has lagged behind and should therefore expand its naval presence.
The official Chinese party People's daily assailed Japan for its "disgraceful history and wrong politics" Japan would pay the price even though it had "an advanced economy and powerful patron [i.e. the United States]."