KAMAISHI, Japan (Reuters) - Japan's worst crisis since World War Two has put its military under a rare spotlight as soldiers search for survivors, clear away rubble, deliver aid and help exhausted engineers avert a nuclear catastrophe.
Japan's military is constitutionally limited to defending the country, but the March 11 earthquake and tsunami coincided with a national debate over whether it can play a bigger role in the face of an assertive China and a belligerent North Korea.
The Self-Defense Forces (SDF), as Japan's military is known, has dispatched 100,000 troops to the quake-crippled northeast coast. They search flattened towns for bodies and survivors, clear roads and deliver fuel, water and other supplies.
They have also toiled for days spraying water on overheating reactors from helicopters and water cannon. Television news broadcasts show soldiers swapping green fatigues for white anti-radiation gear.
Their work is highly visible, in contrast to the erratic response of Japan's political leaders, who face public criticism for issues ranging from getting medical supplies to evacuation areas to their initial handling of the nuclear accident.
Prime Minister Naoto Kan has yet to visit the devastation first hand. Local officials said it was too much of a burden to host him at first. On Monday, bad weather scrapped a visit.
Into that vacuum has stepped the military, a comforting presence amid despair and the devastation of a disaster that has left more than 21,000 dead or missing.
Japan's troops have been in an awkward position because of a post-war constitution that renounces the right to wage war. The constitution bans the maintenance of a military but has been stretched to allow forces strictly for self defense.
"The response has been very positive for us and everyone has been thanking us," said Naoki Maeda, 36, part of an SDF team distributing meals in Kamaishi, Iwate prefecture, as survivors hungry for food and water gathered in tents.
"Reconstruction efforts are a part of our duty. We just want to do what needs to be done and help people and their basic living needs."
The number of mobilized SDF personnel is nearly half the 230,000 troops of the entire standing military. The SDF boasts advanced equipment, but Japanese forces have not been battle tested since World War Two.
But conservative politicians want to normalize Japan's gun-shy, post-World War Two defense policies, a desire that has intensified due to concerns about North Korea's nuclear and missile programs and China's emergence as a regional power.
The United States has also pressed Tokyo to take a bigger role in global security.
Its strengthening public profile could work in the favor of advocates calling for a bigger military role, although substantial changes are unlikely given misgivings about Japan's military ambitions from China and South Korea, which suffered from Tokyo's aggression in World War Two.
"It is now easier for the Self Defense Forces to assert that they are useful in Japan for the Japanese people," said Narushige Michishita, Associate Professor at the National Graduate Institute for Policy Studies in Tokyo.
"But I don't think this will lead to the reinforcement of Japan's defense or reinforcement of their role as a military organization," he added.
With many critical of local authorities, especially over the haphazard provision of supplies to areas devastated by the tsunami, small fishing towns such as Kamaishi in Iwate prefecture are pinning their hopes on the military's help.
"It doesn't matter where they come from, even from outside Japan, troops or doctors, just as long as they can spend just one day here and they can help us," said Kenji Sano, a survivor in Kamaishi. "I would be so happy and so touched."
Additional reporting by Jon Herskovitz and Kiyoshi Takenaka. Editing by Jason Szep and Daniel Magnowski