TOKYO: Hayao Miyazaki's new film is already a box office hit but its themes about the dangers of nationalism and war have set up the Oscar-winning animator for unprecedented criticism.

"The Wind Rises", which debuted at the top of the Japanese box office last month and has a competition slot at the upcoming Venice Film Festival, is based on the man who designed Japan's feared Zero fighter plane used in World War Two.

Commentators see it as a veiled warning that Japan may again be heading in a similar direction. Miyazaki, 72, emphasized that warning in a scathing essay in mid-July about proposals by Prime Minister Shinzo Abe to revise Japan's pacifist constitution.

"The time shown in the movie resembles the present," said film commentator Ryusuke Hikawa, referring to the 1923 earthquake that devastated Tokyo and the 1930s Depression - parallels to the 2011 earthquake and tsunami and Japan's long-stagnant economy.

"After the quake there was turmoil and Japan began heading towards war. It is possible to feel some similarities ... The economy was bad and psychologically it was a situation of having to do something big, and that's how things got nationalistic."

Abe, whose coalition won parliamentary upper house elections last month, has pledged to revive the economy, bolster Japan's defense posture and revise the constitution. Voters are wary of his constitutional views but welcome his economic policies.

Marked by Miyazaki's vivid colors, the story of engineer Jiro Horikoshi is his first film centered on an historical figure and real events - Japan's march towards war.

Much of the menace is masked by a romantic subplot, while Horikoshi's work on the Zero comes off as a noble effort by a man in love with planes and flight. That is a love shared by Miyazaki, whose father made parts for warplanes.

"This movie is nothing more than a hymn to the Zero," said one Internet commentator.

Critics and some viewers have dismissed the idea, but fears that others would see the film as praising war may have led Miyazaki to write the essay. He also criticized environmental destruction in the Oscar-winning 2001 film "Spirited Away".

"One can only be appalled by the lack of historical sense and fixed convictions on the part of top political leaders," he wrote, without mentioning any names, in a magazine put out by his studio and then carried on the internet. "People who have not thought enough should not be messing around with our constitution."

Critics noted "The Wind Rises" is short on the whimsy of most Miyazaki movies, many of them hits abroad. No announcement about the timing of overseas openings could be made yet, a studio spokeswoman said.

Miyazaki's film and essay "need to be seen as a set", critic Yuichi Maeda said.

"He didn't want people to mistake what he wanted to say, to think that war is somehow glorious," Maeda wrote.

"Right after you see the first successful Zero flight there's a scene where the ground is littered with smashed planes, which is his message right there."

An online article about the film was bombarded with nearly 3,000 comments, from disappointment at Miyazaki's "intrusion" into politics to those calling him a traitor. Ultimately, "The Wind Rises" seems to leave viewers with a less heavy message.

"Horikoshi worked hard for his dream," said housewife Yukari Yamazaki. "It made me feel that all young people should find their dreams and give their all to make them come true."