Forty-six nations called for a ban on cluster bombs by next year. The declaration was adopted Friday by 46 of the 49 nations attending a conference in Oslo. Poland, Romania and Japan opted out. Major cluster bomb manufacturers, including the United States, Russia, China and Israel, are boycotting the conference, saying the proper forum for such talks is the U.N. Convention on Conventional Weapons. Israel, which has been criticized for the cluster munitions it used in Lebanon during last summer’s war with Hezbollah, usually prefers not to resolve such issues in U.N. fora. Hezbollah also used cluster bombs in that war. Organizers of the Oslo conference say that although the declaration would be non-binding, similar processes have culminated in binding treaties, for instance a land-mines treaty passed in 1997.