Contrary to Abe's reiteration, the term "deep remorse" is ambiguous and expressing it does not necessarily mean he will reflect upon the wars that Japan waged on its neighbors. Many Japanese right-wingers, including Abe, believe Japan was defeated in WWII because of the then government's arrogance that made it challenge, not befriend, the almighty US.

The fact is, however, China's War of Resistance Against Japanese Aggression (1937-45) dealt the final blow to the imperial Japan. With regard to his speech in Washington in April, whether Abe was expressing "deep remorse" over Japan's sudden attack on Pearl Harbor in 1941 or its full-scale invasion of China in 1937, remains unclear. Hopefully, his Aug 14 speech will make that clear.

Abe's apology, if he does render one, will be of great historical significance to all countries that suffered Japanese aggression. In its absence, China and other Asian countries will remain alert to Abe's moves, such as efforts to remilitarize Japan using the pretext of the US-Japan alliance and his new security bills, which could trigger an arms race in East Asia and destabilize the region.

Cooperation will benefit China and Japan both, while confrontation will have the opposite effect. This is most evident in bilateral trade, which reached $312 billion in 2014 - about 21 percent of Japan's total foreign trade and 7.5 percent of China's. If tensions are not defused, both countries will suffer, only that Japan will suffer more because it will become even more difficult for it to narrow the huge trade deficit with China. Official figures show that at the beginning of last year, more than 54 percent of the Japanese enterprises operating in China were willing to expand their businesses. Yet declining Japanese investment in China - it dropped by more than 38 percent year-on-year in 2014 - presents a different picture.

Apparently, the inherent political uncertainties in China-Japan relations have played a role in shrinking economic exchanges. These uncertainties can only be removed if Abe sincerely apologizes for Japan's militarist past. The answer will be known in a day.

The author is a professor of Japanese studies at Fudan University in Shanghai.