In the last of a special series on Japan, BBC News Online's Sarah Buckley reports on Japan's changing attitudes to its role in global security.
Shotaro Kodama, a 74-year-old who lived in Hiroshima when the atomic bomb was dropped in 1945, is worried Japan will revisit the dangerous aggression of its past.
"The probability is that Japan will fight again in a war and I don't like it," he said.
Such worries are understandable.
Sending troops to Iraq has already stretched Japan's constitution
As domestic alarm rises over the potential threat posed by neighbours China and North Korea, and Washington seeks allies to help shoulder the burden of its foreign policy, Japan is coming under increasing pressure to play a more assertive role on the international stage.
Its leaders have responded by instigating a wide-sweeping review of Japan's UN role, its constitution, and its general security policy.
But any changes are controversial in a country which is still haunted by the atrocities it wreaked during its wartime occupation of the region.
Japan's post-war constitution forever renounces war, and its soldiers have not fired a shot in conflict since 1945.
Japan's WWII memories have hampered its international role
The government already went too far, in the eyes of people like Mr Kodama, when it pushed through legislation last year to allow it to send troops to Iraq.
The 550-strong contingent is only there to help rebuild the nation, not to fight. But many fear it could get drawn into conflict in what is, in reality, still a combat zone.
Yet Washington would like Japan to do more, for example by extending the military's powers so that they can fire to defend their allies, and not just themselves.
Some lawmakers in Japan would also like a freer hand, frustrated not only by the country's impotence on the international stage, but by its inability to adequately defend itself.
"They think Japan should stand up for itself much more.... should be an equal partner with the United States," said Christopher Hughes at the University of Warwick.
The most obvious threat to Japan is North Korea, which demonstrated in 1998 that it had missiles which can reach Japan. It is also believed to have nuclear weapons.
But analysts say the real, unspoken, worry is China - Japan's long-term rival for regional trade and resources.
As a result, Japan is currently undertaking a comprehensive review of its security policy. This week, a government panel recommended a series of changes, including
the relaxation of its arms sales ban, a debate on offensive missile capability, and a fuller international policing role for its armed forces.
Separately, the ruling Liberal Democratic Party is reviewing the constitution, including the pacifist Article 9, and wants to hold a referendum on possible changes in about five years' time.
How far to go?
Japan cannot wholly reinvent itself. Severing its post-war US alliance and declaring itself completely neutral, for example, is unrealistic for a country so reliant on Washington for security and trade.
PACIFISM UNDER THREAT?
Japan's constitution renounces the use of force
This has been stretched to allow self-defence troops
1992 law allowed troops to join UN and relief work overseas
2003 law said troops could go to non-combat zones in Iraq
PM Koizumi wants to give Japan even greater powers
It is lobbying for a permanent seat on the UN Security Council, which would give it more say in international diplomacy. But analysts think it unlikely the current permanent members will welcome a new face, and thus the dilution of their powers.
But Japan can shape its security policy, and in doing so decide how it negotiates an identity for itself in the 21st century.
Taro Kono, an LDP lawmaker who sits on Japan's parliamentary select committee for constitutional reform, denied that the security review under way marked the start of a creeping militarism.
Chinese football fans showed their distrust of Japan earlier this year
"There's a big distinction between participating in UN peacekeeping resolutions and invading China again," he said.
Ben Self, US-Japan security analyst at the Stimson Center in Washington, was equally sanguine, arguing that Tokyo was only taking tiny steps.
"I think it's political manoeuvring to show Washington that movement is there without actually going there yet," he said.
But Warwick University's Christopher Hughes argued that Japan's military role had been expanding at an accelerating rate over the last few years, suggesting Japan's "overall trajectory" was towards building a full combat force.
It is difficult to judge how the public feel. Opinion polls by major newspapers to mark Constitution Day last month all agreed that for the first time in half a century a majority of Japanese were in favour of revising the constitution.
Akira Kawasaki from the Japanese NGO Peace Boat complained that the public was not helped by unsophisticated debate predicated on broad questions of national pride such as "If you don't have any kind of military force, how can you protect your own country?"
He said the country needed to make the debate more specific and honest - for example, by acknowledging Japan's ties to the US - in order to give the public something to get its teeth into.
It is not clear how much change Japanese people can stomach. But the issue may at least force more public discussion about Japan's wartime past, and its future role.
"Usually Japanese people don't like discussion or expressing opinions openly, and now is a good time to have a discussion about this basic problem," said Mr Kodama.