But many in the army apparently had no idea that they might have to do some fighting

MASAKI TOMIYAMA’S fight seems quixotic. He was happy for his son to join one of the world’s biggest, best-equipped armies, but cannot abide the idea that he might have to do any fighting. “I was very angry when I heard my son was being trained to kill people,” says Mr Tomiyama—so angry, in fact, that he decided to sue the Japanese government for violating the country’s pacifist constitution. “I will never allow him to go to war—that’s not why he signed up.”

Japan’s constitution, cobbled together by the Americans in a few hectic days in 1946, prohibits the maintenance of land, sea or air forces. But at the height of the Cold War it seemed otherworldly for a rich ally of the West, with unresolved territorial disputes with all its neighbours, to have no armed forces at all, so in 1954 the government set up the “Self Defence Forces”.

The SDF was to exist “to protect the peace and independence of Japan”. But it was controversial all the same. For decades the biggest opposition party wanted it abolished. Such was the controversy, recalls Noboru Yamaguchi, a former SDF lieutenant-general, that service members slipped into civilian clothes before leaving barracks to avoid abuse from the public.

The SDF remains one of the world’s odder armies. It has never fired a shot in battle. Its main role, for many Japanese, is disaster relief. Yet it has a larger navy than France and Britain combined, including four huge “helicopter carriers”.

Hawkish members of the ruling Liberal Democratic Party (LDP) have long wanted to make the SDF more like a normal army. In 2015 the government passed several security bills “reinterpreting” the constitution to allow the SDF to engage in what Shinzo Abe, the prime minister, called “proactive pacifism”—participating in peacekeeping missions and the like. The move triggered protests and bitter parliamentary wrangling. Mr Abe was acting out of nostalgia for the time when Japan was a great power, critics said. They predicted that the legislation would ensnare Japan in foreign wars and trigger a stampede from the SDF’s ranks.

Seventeen months on, the force has actually swelled slightly, to 227,000 personnel, but there has been a sharp decline in the proportion of those training to become officers at the National Defence Academy of Japan who actually end up joining the SDF. Demography is not working in the SDF’s favour: the population of 18-year-olds has shrunk by a million over the past two decades, making recruitment difficult. The issue, says Alessio Patalano of King’s College London, is not just the number of would-be soldiers, but the quality.

The defence ministry has responded with a lavish and sometimes creative promotional drive, doubling its public-relations budget and enlisting the help of cartoon characters, pop stars and schools. Children at one secondary school even found the number of the local SDF recruitment office printed on their toilet paper. Much of the drive explicitly targets a neglected audience: women. Only 6% of the SDF’s employees are women; it wants to raise that to 9% by 2030.

Demands for a more muscular SDF will grow. China’s defence budget has increased 44-fold in three decades, points out Yoshitaka Shindo, an LDP hawk. A new paper by the Institute for International Policy Studies, a think-tank considered close to the LDP, says Japan could be “profoundly affected” by Donald Trump’s “America first” policy. It believes Japan should develop greater capabilities of its own, including cruise missiles. “We must respond to America first-ism with Japan first-ism,” says Masato Inui, executive editor of the Sankei Shimbun, a right-wing newspaper.

But aversion to anything that smacks of militarism runs deep. Last year 350 SDF personnel were dispatched to South Sudan as part of a UN peacekeeping force. The troops are only there to repair infrastructure and are supposed to be withdrawn if there is fighting between local militias (so far, the government says, there has only been “conflict”, which is apparently quite different). But, for the first time, the SDF has been authorised to use weapons to defend civilians and UN staff. Opponents of the policy, including Japan’s most widely circulated liberal newspaper, the Asahi Shimbun, are campaigning to have the troops withdrawn. “We worry about troops who get injured,” fretted a recent editorial. Mr Abe has suggested that he will resign if any Japanese soldiers are killed.

Young people in the SDF joined to help the victims of earthquakes and tsunamis, says Norikazu Doro, a former service member. “They had no idea they were joining an army that could one day go to war.” Mr Tomiyama is one of several parents who have taken the government to court. He says his son signed up to help and defend his country, not fight other nations’ battles. “The principle was that only if we were attacked would we attack,” he says. “That principle has been voided.”