With Tuesday's decision for France to host the multibillion-dollar experimental ITER nuclear fusion reactor, many experts predict Europe will take the lead in developing the promising energy source.
Some said Japan, which withdrew its bid to host the 1.3 trillion yen International Thermonuclear Experimental Reactor project, must now reinforce its fusion research if it is to remain one of the top countries in the field.
But other scientists and citizens' groups are urging the government to use this opportunity to change its policy on chasing fusion.