TOKYO - Prime Minister Shinzo Abe is hitting a speed bump in his drive to ease constitutional limits on Japan's ability to fight abroad, as members of his own coalition put up obstacles that could force him to delay or water down the move.
Abe has made clear he will press on with changes to free the military from the constraints of the pacifist constitution, but members of his own party are urging caution and his coalition partner is dubious about the wisdom of the historic - and unpopular - change.
Allowing the Self-Defence Forces to aid the United States or other allies under attack would mark a turning point for Japan's military, which has not fired a shot in conflict since World War Two. It would increase the chances of involvement in wars overseas - and almost certainly strain already fraught ties with neighbours China and South Korea.
After parliament last week enacted Abe's budget for the coming fiscal year, so-called collective self-defence looks set to dominate the remaining three months of this session.
Other aspects of Abe's agenda, which seeks a more muscular military and a less-apologetic foreign policy, have also run into trouble. His December visit to Tokyo's Yasukuni Shrine, seen by critics as a symbol of Japan's wartime militarism, upset not only Asian neighbours China and South Korea but security ally the United States, which expressed "disappointment".
Abe has had to back away from any attempt to revise a 1993 government statement apologising for government involvement in forcing Asian women to serve as prostitutes for Japanese soldiers in World War Two under US pressure to repair frayed ties with Washington's other key Asian ally Seoul.
The government is not making a direct assault on the constitution to allow collective self-defence, but instead aims to reinterpret the charter to authorise the use of force to help allies abroad. But even some of Abe's political allies are wary of that approach.
"I think it is wanton for the government to change overnight the interpretation of the constitution to allow the exercise of the right of collective self-defence," Natsuo Yamaguchi, leader of dovish coalition partner New Komeito, said over the weekend in one of his strongest statements on the topic.