Japanese Prime Minister Shinzo Abe's statement marking the 70th anniversary of the end of World War II lacks sincerity and is an "insult" to victims of Japan's military and sexual aggression, a US historian told Xinhua on Saturday.

In his statement, Abe mentioned previous governments' apology for Japan's wartime past, but refrained from offering his own.

Peter Kuznick, history professor at American University, said Abe tried to walk a tightrope between his own belief that Japan's wartime behavior was generally acceptable and the collective moral judgment that Japan was an aggressor nation whose behavior was grotesque and indefensible.

"The result is a bland statement that neither accepts responsibility for Japan's past aggression in a way that will satisfy China, the Koreas, and other victims of Japanese atrocities nor does it infuriate Japan's right-wing nationalists, who form the backbone of Abe's supporters," Kuznick said.

Calling him a "notorious historical falsifier", Kuznick said Abe's failing to offer an apology "comes as no surprise," adding that the Japanese prime minister's actions are more dangerous than his words.

"He is remilitarizing Japan. He is effectively consigning Japan's peace constitution to the dustbin of history, which understandably alarms all of Japan's neighbors," the American historian said.

"The real point is not what he says in this hollow contrived statement but what he does in practice as Japan's prime minister," he added.

Should Abe abrogate Japanese Constitution's Article 9, the clause that renounce war, Kuznick warned, the future of Japan and the rest of Asia could get "much much uglier."