Image copyright AFP Image caption Under Shinzo Abe, is previously marginalised right-wing sentiment gaining ground?

Tensions between China and Japan are at their highest level for decades as Tokyo defies pressure from Beijing over disputed East China Sea islands. As US President Barack Obama tours the region, Charles Scanlon asks whether Prime Minister Shinzo Abe is deliberately fanning the flames of nationalism in his drive to make Japan a more assertive and self-confident power.

The forlorn elderly couple handing out leaflets on a street corner on the outskirts of Tokyo had a bizarre and scarcely credible story to tell.

They said that their 13-year-old daughter had been kidnapped by North Korean secret agents while returning from badminton practice.

The couple told anyone who would listen that she was probably grabbed by frogmen emerging from the ocean near their home and bundled off to North Korea on a submarine.

To some passers-by, 14 years ago, it sounded as if the couple's grief had turned to paranoid fantasy.

That was also the view of the police and much of Japan's diplomatic and political establishment.

But there was one ambitious politician, from a famous political family, who did take them seriously.

Image copyright AFP Image caption Shigeru and Sakie Yokota have campaigned for years to find out what happened to their daughter, Megumi

Shinzo Abe took up the cause of the Yokota family, and their missing daughter, Megumi, and helped drive it to the top of the political agenda.

He and the then prime minister, Junichiro Koizumi, went to Pyongyang and secured a stunning confession from the North Korean leader, Kim Jong-il. Their visit led to the return of five abducted Japanese citizens - but not several others, including Megumi, who the North Koreans claimed had committed suicide.

The Yokotas still count on support from Mr Abe, whose government recently negotiated a first-ever meeting with their 26-year-old grand-daughter, born to Megumi and an abducted South Korean who she married during her years of captivity.

Revisionist circle?

Mr Abe's career received such a boost from his championing of the abduction issue that he is now serving his second term as prime minister.

He was able to present himself as a rare beast among Japanese leaders - someone who cared about ordinary people and was prepared to stand up to hostile neighbouring countries.

For many Japanese, frustrated by long years of economic stagnation and a succession of weak prime ministers, Mr Abe brings hope. He has a plan to revive the economy with aggressive stimulus measures, dubbed Abenomics. He is also admired for standing firm in the face of what is seen by many as bullying by China and the two Koreas.

Image copyright AFP Image caption How Shinzo Abe handles ties with China in coming years could shape events in the region

For anyone reading newspapers or watching television in China or the Korean peninsula, however, Mr Abe appears in a more sinister light. He is portrayed as a hard-line nationalist and militarist bent on rearming Japan and asserting its dominance in the region.

Shinzo Abe remains an ambiguous figure. He tries to cultivate the image of a well-meaning patriot, set on restoring the self-esteem of a country down on its luck. But some on the left of Japanese politics suspect a grander strategy - to undermine Japan's post-war pacifist culture and rebuild the military against a resurgent China.

"Shinzo Abe has shown he can be cautious and pragmatic," says Garren Mulloy, who specialises in the Japanese military at Daito Bunka university. "He may be a nationalist, but it's really some of those around him who are the real problem - some are revisionists who are seeking to challenge the established post-war order."

The threat from China, with its fast-growing naval power and direct challenge to Japanese sovereignty over the disputed Senkaku or Diaoyu islands, has boosted Mr Abe's popularity despite the instinctive suspicion of nationalistic rhetoric felt by many in Japan.

Mr Abe has sent out signals that encourage rightists, who contest Japanese war guilt and favour a more authoritarian country with the emperor at its core.

His visit late last year to the Yasukuni war shrine was a clear sign of his growing confidence. The shrine honours the country's war dead including convicted war criminals, and symbolises Japan's old martial spirit.

The government has also flirted with revisionist views of Japan's war-time aggression without firmly committing itself either way.

The cabinet's suggestion it was reconsidering the evidence behind a 1993 apology for the sexual enslavement of hundreds of thousands of Asian women sparked such an outcry at home and abroad that Mr Abe intervened to say that the apology would stand. It is a touchstone issue for nationalists, who insist that Japan's image has been deliberately smeared by ill-intentioned foreigners.

Image copyright AP Image caption South Korean protesters accuse Japan of glorifying its militaristic past

Some influential conservatives in Japan also deny that the Nanjing massacre of 1937 took place and want the government to withdraw its central apology for wartime aggression.

Mr Abe has been more cautious. But his language is carefully calibrated to evoke nostalgia for the past with references to the "beautiful country", an image of a mythical pure Japan free of contamination from western liberalism and individualism.

The nationalist world view portrays Japan as an innocent victim of rapacious and hypocritical foreigners. Right-wing academics, politicians and commentators believe that Japan was forced into a defensive war in the Pacific and was obliged to accept victors' justice after its defeat.

Denying Japanese guilt for the war is seen as a key step in rebuilding national pride, and establishing independence from the United States.

Naval power

Some see a clear connection between such revisionism and Mr Abe's move to reinterpret a key article in the constitution that restricts the activities of Japan's military

But Prof Mulloy says this concern is overblown. "The idea that Japan is being militarised is fanciful. Military spending has actually fallen until recently," he said.

Image copyright Getty Images Image caption The Japanese navy is one of the best in the world

"The Japanese navy is one of the best in the world after the United States. But its capabilities are front-loaded, with very little in support. The navy probably couldn't sustain effective combat operations against China for more than two weeks."

Others agree that China is deliberately making a false link between Mr Abe's policies and the militarism of the past to try to weaken Japan internationally.

"Whatever the views, often objectionable, of these revisionists, there is absolutely no evidence that Japan is returning to any form of expansionist military policy. Indeed... recent changes in Japanese defence policy bind Japan in to its allies and partner countries, and further reduce any possibility of an aggressive military posture," says Simon Chelton, a former British defence attache in Tokyo.

The present government, however, is increasing military spending and deploying forces to the south and west to meet the threat from China.

Japan is also working to strengthen its alliance with the United States and forge military ties with other Asian countries that feel threatened by a rising China.

Some in the Japanese foreign ministry worry that Mr Abe's ties with revisionists and war-guilt deniers could be counter-productive. He has already upset Washington by ignoring advice not to go to the Yasukuni shrine.

Opinion polls also indicate that anti-Chinese sentiment has surged to new levels in Japan.

Many Japanese are infuriated by continuing demands for apologies from Chinese communists who make no attempt to address the reality of their own history. They see the constant references to past crimes as an attempt to weaken Japan's standing in the world and shake its hold on disputed islands and offshore resources.

The fear is that Mr Abe, or those around him, could exploit such sentiment for their own ends.

What is clear is that angry nationalism is on the rise in China and Japan, and the two feed on each other in a dangerous spiral.

Whatever Mr Abe's true intentions, he has shown little inclination, as he attempted in his first term, to ease the dangerous tension with China and refocus on economic co-operation between the world's second and third largest economies.