Final answer:
The Beatles' 1966 Japan tour faced controversy due to their performances at the culturally significant Nippon Budokan and the tension caused by Western influences in post-war Japan.
Step-by-step explanation:
The controversy surrounding The Beatles tour of Japan primarily revolved around their performances at the Nippon Budokan in Tokyo in 1966. The venue was traditionally used for martial arts and the decision to hold a rock concert there led to significant pushback from those who felt that it was disrespectful to the cultural importance of the site. Moreover, there were nationalistic undercurrents as some groups protested the presence of a Western band during a period where Japan was still grappling with post-war identity and Western influence. This animosity was palpable, leading to security concerns and requiring a strong police presence to ensure the safety of the band and concertgoers.