Cooperation between Japan and Poland dates back to the 1904-05 Russo-Japanese War. During this time, activists vying for Polish independence cooperated with Japanese intelligence, providing them with information about the movement of Russian troops. In fact, despite Poland not yet being recognized as an independent country, it was deemed a “Samurai Nation” by Japanese author Nitobe Inazō in his 1904 book, Bushido: The Soul of Japan.
After the First World War, Japan officially recognized Poland as an independent state. This marked the beginning of international relations between the two countries. After the conflict, Japan supported Poland’s efforts to join the League of Nations as an independent nation.
In 1923, the Polish military taught the Japanese Army cryptography, sending officers to Japan to teach encryption skills. The Japanese had been struggling to break Soviet radio signals for over a year at this point. With the help of the Poles, they were cracked in just a few weeks.