Shinzo Abe's tough stance over Japanese citizens kidnapped by North Korea decades ago helped catapult him to a first, brief stint as Japan's prime minister.
Back in office for well over a year, Abe is now pushing for answers in an issue that has dominated his career, but must ensure he does not fall out of step with Japan's biggest ally, the United States.
Nearly 26 years after first learning that Japanese citizens might have been abducted by Pyongyang's agents, Abe is working to uncover the fate of a dozen Japanese nationals says were kidnapped along with hundreds of other compatriots who may also have been snatched away.
After talks with North Korea in Stockholm, Abe announced last week that Pyongyang would reopen a probe of missing Japanese. In return, Japan will ease some economic sanctions when the probe starts and consider humanitarian aid later.
Abe's commitment to solving the mystery of the kidnappings is not only a matter of personal sympathy for the victims. It also reflects his agenda to build a stronger, more self-reliant Japan. But the push could put Japan out of line with the United States and South Korea, the two other nations most at risk from the North's missile and nuclear programmes.
With North Korea reportedly on the verge of a fourth nuclear test, maintaining close unity will be crucial for the allies.
On Tuesday, Japan's foreign minister said Abe might consider visiting Pyongyang if that would help get results, but Abe later told reporters it was too soon to decide, Japanese media said.
Japanese officials stress Tokyo is in close touch with both Washington and Seoul, and some pundits say Japan will calibrate its actions to avoid upsetting the United States.
"I think Mr. Abe is well aware that for him, Japan, and many other countries in East and Southeast Asia, the real issue is China, and how the United States is engaged on that issue," said
Jun Okumura, visiting scholar at the Meiji Institute for Global Affairs. "I don't think Mr. Abe can afford to incur the anger of the United States."
Sung-Han Kim, a former vice minister for foreign affairs in South Korea and a professor at Korea University, said at a conference in Kuala Lumpur: "Japan's sanctions are not a big portion of the sanctions on North Korea. I think Japan is smart enough to control this."
U.S. officials have privately asked Japan to keep it posted on its dealings with the North, but aired no public complaints.
"We will ensure that our alliance evolves to reflect the shifting security environment," U.S. Defense Secretary Chuck Hagel said on Saturday, two days after Abe announced the deal with Pyongyang.
PERSONAL AND POLICY REASONS
Abe has both personal and policy reasons for pushing aggressively to achieve closure over those kidnapped by Pyongyang's agents in the 1970s and 1980s to help train spies.
"It's a signature issue. It's why he catapulted out of the back benches to the prime minister's office," Jeffrey Kingston, director of Asia studies at Temple University's Japan campus.
"He's a guy with spine who will stand up for Japan."
By Abe's own account, he first heard of the kidnappings in 1988, when the parents of abductee Keiko Arimoto visited the office of his father Shintaro, a senior member of parliament for whom the young Abe was working as an aide.
"At first, I was half sceptical that it was really possible for a nation to kidnap the citizens of another country, but as I looked into it, I had to believe in North Korea's crime," Abe wrote in his 2006 book, "Towards a Beautiful Country".
Many Japanese had long dismissed accounts that citizens such as Arimoto, who disappeared in Europe in 1983, and 13-year-old Megumi Yokota, who vanished on her way home from school in 1977, had been spirited away by North Korean agents.
Abe, however, adopted the topic as his own when he was first elected to parliament in 1993 and helped found a group of like-minded lawmakers dedicated to uncovering the truth in 1997.
For Abe and his conservative colleagues, the kidnappings go beyond human tragedy, resonating with their view that Japan's ability to defend its people was weakened by the U.S.-drafted, post-war pacifist constitution, a charter he wants to revise.
When North Korean leader Kim Jong-il shockingly admitted to 13 kidnappings at a September 2002 summit with then-prime minister Junichiro Koizumi, Abe - along on the trip as Koizumi's aide - grabbed the public spotlight when it was reported that he had demanded Koizumi leave the meeting unless Kim apologized. Kim apologized and pledged to punish those responsible.
Abe, his popularity assured in large part due to his tough stance toward Pyongyang, succeeded Koizumi in 2006, but made little headway on abductions or anything else before quitting after just a year due to political deadlock and ill-health. But allies who shared his passion for the abductees issue were among those who helped stage his comeback five years later.
Abe has kept the abductions as a top priority while focusing on economic revival and beefing up Japan's security policy. Doubts persist, however, over whether Pyongyang's probe will yield results - it failed to keep a similar promise in 2008.
Whether Abe can achieve closure despite hints by Pyongyang of possible survivors is also unclear.
Japan has identified 17 citizens it says were abducted, of whom five came home in 2002. North Korea has said another eight were dead, but Tokyo wants better proof of their fate as well as other missing persons who may also have been kidnapped.
"Whatever credible story North Korea produces, it is almost certain to be a story the Japanese public will not enjoy," said Okumura at the Meiji Institute.