In retaliation, Abe paid a highly symbolic visit to Yasukuni Shrine in late December, drawing harsh condemnation from foreign ministries across the Pacific. The controversial memorial to Imperial Japan’s war dead, including Hideki Tojo and 13 other World War II-era war criminals, is a touchstone for the polarizing debate on Japanese nationalism, militarism, and historical memory in East Asia. Few actions by a Japanese prime minister could have been more provocative to China, where patriotism is closely intertwined with anti-Japanese sentiment.

Relations plummeted thereafter. In British newspapers, dueling editorials devolved into Chinese and Japanese officials comparing one another to Lord Voldemort, the fictional archvillain from the Harry Potter novels. Cui Tiankai, China’s ambassador to the United States, invoked Japan’s aggressive imperial past in a Washington Post op-ed, while Kenichiro Sasae, his Japanese counterpart in Washington, retaliated in an op-ed of his own by declaring, “It is not Japan that most of Asia and the international community worry about; it is China.”

Standing at the center of controversy is a familiar feeling for Shinzo Abe. A conservative nationalist, he famously denied in 2007 that there had been any coercion of the 250,000 foreign “comfort women” who were forced into sexual slavery in Japanese military brothels during the war. Abe also supported revising school curricula to downplay Japanese wartime atrocities, a move that has previously prompted protests and diplomatic rebukes in China, South Korea, and the Philippines, whose people suffered greatly under Imperial Japanese rule in the early 20th century.

To this day, World War II’s scars run deep in East Asian politics and shape Japan’s defense policies. The conflict’s horrors motivated the Allied powers to rewrite many of the defeated Axis nations’ new constitutions, including Japan’s, to inhibit future aggression. Article 26 of the German constitution, drafted in 1948, declares that “[a]cts tending to and undertaken with intent to disturb the peaceful relations between nations, especially to prepare for a war of aggression, shall be unconstitutional.” Italy similarly “rejects war as an instrument of aggression against the freedom of other peoples and as a means for the settlement of international disputes” in Article 11 of its post-war constitution. Article 9 of Japan’s constitution, however, goes much further than the others in abolishing militarism:

1. Aspiring sincerely to an international peace based on justice and order, the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as a means to settle international disputes. 2. In order to accomplish the aim of the preceding paragraph, land, sea, and air forces, as well as other war potential, will never be maintained. The right of belligerency of the state will not be recognized.

These prohibitions leave Japan, the world’s third-largest economy, heavily reliant on the United States for self-defense and far weaker than its neighbors. Japan spends roughly $59 billion per year on defense, for example, while China spends more than $166 billion. The Japanese Self-Defense Forces, or JSDF, which is strictly forbidden from conducting combat operations, is only one-third the size of South Korea’s armed forces, one-sixth the size of North Korea’s, and one-tenth the size of China’s.