China did Korea a big favor when it opened Sunday a memorial hall in Harbin to honor Ahn Jung-geun, a Korean independence fighter who assassinated Hirobumi Ito, who laid the foundation of modern Japan and Japan’s annexation of Korea, more than 100 years ago.

The 200-square-meter memorial hall, built in Harbin Station, where Ahn shot to death the Japanese colonial leader on Oct. 26, 1909, exceeds President Park Geun-hye’s expectations in terms of its significance.

During a summit in Beijing with Chinese leader Xi Jinping last June, Park asked that China allow Korea to set up a stone monument for Ahn at the site of the assassination. Xi accepted Park’s request and, as it turned out, he has done much more than asked.

Few expected China would go so far, given that it had until last year refused to even allow Korea to erect a stone monument out of concern that it would offend Japan, the provider of a huge amount of development aid to China.

The about-turn comes against the backdrop of Japan’s move to revive militarism. Japanese Prime Minister Shinzo Abe has recently visited the Yasukuni Shrine, a symbol of Japanese militarism, and has been seeking to revise Japan’s “peace constitution” to obtain the right to exercise military force in overseas conflicts.

China’s decision to build a memorial hall for Ahn, who is revered by many Chinese, reflects a shared perception between the countries of the threat posed by Japan. It also indicates China’s desire to form a common front with Korea in putting pressure on Tokyo to come to terms with its history.

The governments of Heilongjiang province and Harbin city, which built the hall on behalf of the Beijing government, went to great lengths to make the hall a place to remember and honor the admired Korean hero.

They remodeled part of the VIP lounge at the train station to build the hall. The hands of the clock hung on its wall point to 9:30, the time Ahn fired his pistol at Ito on a railway platform. Visitors to the hall can get a clear view of the assassination site through a large glass window.

The memorial hall displays a bust of the independence fighter, documents introducing his short but heroic life and thoughts, and Chinese leaders’ writings and poems praising him.

Quite understandably, the opening of the hall triggered protests from Japan. Yoshihide Suga, Japan’s chief cabinet secretary, criticized the Korea-China cooperation in honoring Ahn, calling him a “terrorist.”

Japan’s protest is totally unacceptable. China has established the memorial hall for Ahn because, as China’s foreign ministry spokesman Hong Lei pointed out, he is widely respected by the Chinese people.

Before criticizing its two neighbors, Japan needs to reflect on its failure to squarely face up to history. It should realize that it will be increasingly isolated from its allies if it continues to pursue its present course without setting history right. The top priority for Tokyo is to win trust from its neighbors by genuinely apologizing for its past wrongs.