Women's involvement in wartime activities puts them in complex moral positions. Any belligerent activity for either side renders them unconvincing as victims of enemy aggression – the premier feminine role in the myriad reinventions of war. Those who take up arms, women soldiers, are contained within the moral order of gendered warfare as noble, courageous but unusual women. Those who trade in secrets are more problematic to manage in the post-war narratives and oftentimes provoke uncomfortable debates about morality, loyalty and sexual virtue. The woman warrior prepared to take a bullet on the front line is a far less ambiguous moral figure than the woman spy who moves information between opposing forces.

Zheng Pingru (1918–1940) is one such contested Nationalist honey-trap spy from the murky world of Shanghai during Japan's occupation of the city. Pingru's mission was to facilitate the assassination of Ding Mocun (1901–1947), a fearsome security chief-cum-gangster who was collaborating with the Japanese. Japan attacked Shanghai in mid-1937, extending its ambitions to dominate China and its resources. The Japanese took control of the Chinese sections of the Shanghai in 1937 and at the end of 1941 their control reached Shanghai's foreign settlements – the British controlled International Settlement and the French Concession. Japan remained in charge of the city and its population until the end of World War Two in 1945. In this complex context multiple groups competed to negotiate better terms with the Japanese, resulting in a pro-Japan government being formed in 1940 under the one-time Nationalist Party leader, Wang Jingwei (1883–1944). This ‘national’ government's members are today still derided as ‘collaborators’ and ‘traitors’. Throughout these years Shanghai was dominated by a brutal group of men, including Ding Mocun, comprising a security apparatus of secret police, assassins and gangsters. Shanghai was a city of drugs, murder, duplicity and terror.

Shanghai's pro-Japan Security Police executed 23-year-old Zheng Pingru in 1940 after a failed assassination attempt on Ding. In 1946, at the end of the War of Resistance against Japan, her execution came to public attention during the trials of ‘traitors against the Han people’.In the trial against Ding, her mother, Zheng Huajun, asserted Pingru's integrity as a courageous ‘patriotic daughter’ and demanded that Ding be held to account for her illegal killing.