In which historical period did the slogan "Traitors be killed without mercy" appear?

Before and after the Anti-Japanese War

The term "Han traitor" later even became part of the legal system. The National Government formulated the "Regulations on Punishing Han Traitors" (1938) and the "Regulations on Dealing with Traitors" (1945 ) as the main tool to attack political opponents (mainly Wang Jingwei's Nanjing government). After the founding of the People's Republic of China, the Communist Party of China also issued the "Instructions on Confiscating the Property of War Criminals, Traitors, Bureaucratic Capitalists and Counterrevolutionaries" (1951) to carry out political struggles against specific individuals.

A reference to the word traitor is: During the Anti-Japanese War, Tan Kah Kee, a businessman who immigrated to Malaysia, proposed to the National Government of Chongqing: "The enemy should treat the enemy as a traitor before he withdraws from our country and declares peace with the country." This The proposal was adopted by the Second Congress of the National Political Participation Association and was called "the greatest proposal in ancient and modern times at home and abroad" by Zou Taofen.