Which religious leader? Hirohito? Hirohito rarely took any direction of the war - at best he enthusiastically endorsed what the ruling militarists wanted. As critical as one could (and should) be about this support, there is plenty of documentation that he tried to tap the brakes on the militarists, but didn't try all that hard. It wasn't until the very end of the war that he directly made a decision, and that was only enabled by a literal tie in the cabinet that allowed him to cast the deciding vote (sorta - more or less, gave him cover to break his role).

He was a war criminal, but not the leader of the war by any means. That was reserved for the militarists - Tojo and Suzuki and others.