Forgotten ally

During the Cold War, the Western nations and China forgot the significance of their wartime alliance against Japan, according to Mitter. "Various things China did changed the path of the war," he said. "Most noticeably the decision ... to continue resistance after (Japan invaded China in) 1937, when they could well have surrendered. Over the course of the war, at their height, (China) was holding down 500,000 Japanese on the Chinese mainland."

Those Japanese troops, tied down fighting Chinese soldiers, could not be deployed in Southeast Asia and the Pacific theater, a handicap that may well have changed the outcome of key battles, according to Mitter. China's resistance also prevented Japan from pushing into new fronts that could have had a significant impact on the war in Europe.

A Japanese incursion into British India would have threatened a source of manpower and resources vital to the fight against Nazi Germany. A push into Russia, an ally that proved crucial in Adolf Hitler's eventual defeat, would also have seen the already beleaguered Red Army fighting on two fronts.

Mitter said Japan planned to conquer China in three months. Almost five years after the initial invasion, when Pearl Harbor was bombed, Japan was still "stuck in the Chinese quagmire".

But China paid a heavy price for its refusal to surrender. By the time the guns finally fell silent in 1945, an estimated 15 million Chinese soldiers and civilians had been killed. To put that in context, the fighting in China is estimated to have accounted for 90 percent of all casualties in the Pacific theater. "These were major contributions that don't tend to be remembered very much in the West," Mitter said.

Conversely, China was only able to stay in the fight because of the supplies and support it received from Western allies, in particular Britain and the United States, which were also engaging Japanese troops elsewhere who could have been thrown against China.

"Without the Chinese contribution, it's much harder to see an Allied victory in Asia during the war," he said. "But without the British and Americans, it's also much harder to see a Chinese victory."

Even less well known are the tales of camaraderie between locals and foreigners in China during the war. In the northeastern city of Shenyang, Chinese people endured alongside captured British, US and Australian troops in the concentration camps, often smuggling in what little food they had to the emaciated foreigners. In Guizhou province, in China's southwest, foreign doctors working for the Red Cross helped save the lives of many thousands of Chinese soldiers and civilians. In western, central and southern provinces, British and Australian commandos trained and fought alongside Chinese guerrilla forces. And in other locations, locals such as Shen staged daring rescues to save foreign prisoners of war.

"This is really a story about both sides helping each other, and I hope that's the view that becomes more lodged in the historical consciousness," Mitter said.

They may be the forgotten allies on the forgotten front, but seven decades on, there are those in China who still remember.