But unfortunately, U.S. responses to denials in each case have been quite different. The famous 2005 Holocaust-denying speech by former Iranian president Ahmedinejad was strongly condemned in the U.S. media and academia, and the U.S. Congress passed bill No. S.RES.337.ATS entitled "To condemn the harmful, destructive, and anti-Semitic statements of Mahmoud Ahmadinejad, the President of Iran, and to demand an apology for those statements of hate and animosity towards..."

The U.S. was certainly right to condemn Ahmedinejad's irresponsible speech. But the question is: Why is it unwilling to respond with the same degree of firmness to the same kind of denial of history in another part of the world? The pilgrimage of Abe and other Japanese politicians to Yasukuni is an even more serious act than simply denying past aggression. The Yasukuni Shrine is the spiritual home of Japanese militarism and was formerly used by the militarists to mobilize support for their wars of aggression. Visiting Yasukuni not only amounts to a denial of Japan's history of aggression, but also implies admiration for the militarism that inspired that history.

What is more, Yasukuni contains the remains of 14 Class A war criminals, including those of Hideki Tojo, widely regarded as the Japanese equivalent of Adolf Hitler.

A comparison with the reactions of China and other countries to the 911 atrocity committed against the U.S. also highlights the inadequacies of the U.S. position. Following 911, Chinese leaders sent condolences to the U.S. president, and strongly condemned the terrorist attack. Even leaders of Muslim countries sent condolences and expressed strong condemnations. Furthermore, China and other countries offered to assist the U.S. in its war against terrorism.

But the weak U.S. response to the Yasukuni visits is not the full story. U.S. indulgence, in some respects, actually encourages Japan to engage in this kind of behavior. This happens not only at official level but also at various other secondary levels. The latest example was U.S. Secretary of Defense Chuck Hagel's visit to Japan this October during which, along with his Australian counterpart, he signed a joint statement with Japan's Minister of Defense. Whatever other purpose this statement might serve, it will certainly encourage Japan to adopt more aggressive positions on historical and other issues.

In a recent personal conversation, a leading U.S. scholar of East Asian studies based in Washington DC expressed his impatience with Chinese scholars who refer to historical issues at international conferences. He insisted that Chinese scholars should spend more time discussing other more "substantial" issues. But how can China not talk about historical issues when Japan's politicians persist in picking at what are still open sores?

Another leading U.S. scholar praised Japan as a good guy who abides by international rules, in an October speech to the Center for Strategic Studies, disregarding entirely Japan's frequent challenges to the post-WWII international consensus. She also chided the Chinese Ambassador to the U.S. for his legitimate criticism of Japan's positions on historical issues.

Some U.S. scholars believe that the Chinese people's views on historical issues are colored by anti-Japanese propaganda in Chinese movies and TV series. But does a history that claimed tens of millions of victims need propaganda to be widely known and remembered? In the Pentagon Memorial for the victims of 911, there is an inscription - stressed by being given a separate line - "we never forget." Why should the Chinese forget their bitter history?