NAGAOKA, Japan – Seven decades after the death of Admiral Isoroku Yamamoto in an aerial ambush in the South Pacific, Japan is still struggling with how to remember the charismatic naval commander who opposed war with the United States, but nonetheless planned the deadly attack on Pearl Harbor.

With tensions once again growing in East Asia and public acceptance of Japan’s military forces beginning to rise, Japan could be ready for a more open discussion of the war era – and its leaders.

“They don’t teach about this period in high schools, so people under 50 years old don’t know much about it. But because of the Senkaku problem, people are beginning to get interested,” said Yukoh Watanabe, an amateur naval historian who attended a private memorial service in Yamamoto’s hometown last week....