Yasukuni is ground zero for an unrepentant view of Japan’s wartime aggression. During World War II, the shrine served as the “command headquarters” of State Shinto, a religion that deified the emperor and mobilized Japanese subjects to fight a holy war at his behest. The private foundation that runs Yasukuni only added the 14 most controversial “souls” [Class A war criminals—ed.] -- surreptitiously -- in 1978.The shrine’s political mission is on blatant display at the adjacent Yushukan museum, run by the same foundation. There, the Class A war criminals are portrayed as martyrs. Japan’s war in China is supposed to have suppressed banditry and terrorism, while its invasion of the rest of Asia is represented as a war of liberation from Western colonialism……It is telling that Emperor Showa (Hirohito), once the head priest of State Shinto, confided to an aide that he stopped visiting Yasukuni after 1978 precisely because the shrine had been tainted by the presence of the Class A war criminals. This explicit politicization of the site also explains why his son, current Emperor Akihito, has maintained the imperial household’s embargo on visits.
Paying respects at the shrine is part of Abe's conservative agenda to restore Japan's pride in its past and recast its wartime history with a less apologetic tone. He also wants to ease the restraints of Japan's post-World War Two pacifist constitution on the military.
…Some political experts said Abe had probably calculated that his relatively high voter ratings, based largely on hopes for plans to revive the economy, could withstand any criticism over his Yasukuni pilgrimage, which would also shore up support in his conservative base.He may also have felt that with ties with Beijing and Seoul in a deep freeze, a visit would hardly make things worse.