Tokyo's shift on the controversial munitions came after Friday's adoption of a draft convention Friday in Dublin, Ireland. Japanese Prime Minister Yasuo Fukuda explained Japan's decision to support the ban to the Japan Times Saturday.
"It has been said for some time that cluster bombs are weapons that could cause humanitarian issues," Fukuda said. "(But) then, there is the issue of (national) security. I think the government considered both aspects thoroughly and came to this conclusion."
The so-called Oslo process began in February 2007, aiming to achieve a treaty banning cluster bombs which often cause high casualties amongst civilians and children. But some countries that possess and use the bombs, including the United States and Russia, have not participated.