BEIJING - July 7 is the anniversary of the beginning of the War of Resistance Against Japanese Aggression (1937-1945). It's a specific date in the memory of the Chinese.

Chinese school children know that the war started at the Marco-Polo Bridge, 15 km southwest of Beijing's city center. Japanese troops attacked a nearby fortress town on July 7, 1937.

Seventy-eight years on, why can we still hear the echo of gunfire from the Marco-Polo Bridge?

The incident signaled eight years of tremendous Chinese suffering at the hands of Japanese. It plunged China into the WWII Asian theater along with the world's anti-fascist forces. More importantly, the anniversary serves as a sober reminder to China, Japan and the world.

During the war, Chinese civilians were killed by gunfire, bombs, gas and biological weapons; women were raped; families were torn apart.

The heinous conflict saw more than 35 million Chinese soldiers and civilians killed and injured, and over 100 billion U.S. dollars in direct economic losses on the Chinese side.

China mounted an obstinate defense against Japanese invaders in the Asian theater, coordinated with the allies' campaigns.

Both the tragedy and meritorious achievement should not be forgotten.

Some may say China would be better off laying down this weighty historical backpack to move on. However, history tends to repeat itself. Chinese know this all too well from the country's 5,000-year history, and thus have a popular saying, "take history as a mirror."

Remembering how the war started requires more than remembering the Marco-Polo Bridge incident, but learning how Japan in 1930s became engulfed by militarism within the country, and how Japan became a believer of social Darwinism and power politics prior to the war which led to autocracy within and military expansion outside the country.

The lessons are particularly relevant today, as rising militarism in Japan since Prime Minister Shinzo Abe took office have kept the world mindful that the specter of militarism, or war, has never really gone away.

In one instance, Japan approved new textbooks that watered down Japan's atrocities during WWII.

Regarding the Nanjing Massacre, textbooks state "captives and civilians were involved" in the tragedy and "casualties were exposed", compared to the original words that the Japanese army "killed many captives and civilians".

Japan attempted to reinterpret the pacifist Constitution to allow its Self-Defense Forces to exercise the right to collective self-defense, a move that will enable the nation to send soldiers into battle on foreign soil.

Abe himself, when faced with a request for comment on the Potsdam Proclamation, which accelerated the end of WWII and established that the war Japan waged over 70 years ago was one of aggression, declined to comment on whether the war was right or wrong.

There is nothing right about aggression. The invasion of China was a devastating tragedy not only for Chinese, but also for peace-loving Japanese people. It left hundreds of thousands of Japanese families torn apart, with husbands and fathers taken away from their loved ones.

What happened seven decades ago should be remembered by both China and Japan, not only to salve deep wounds from the past, but also for a world free from the threat of war in the future.