A skilled organizer, Čermak emerged as a key leader of the labour movement in German Bohemia in the years preceding World War I.
[1][2] During World War I he served as general manager of the Nutritional Association based in Aussig.
[2] In 1918 he was appointed director of the Press Bureau of the regional government of German Bohemia.
[3] After the creation of Czechoslovakia, he became a key leader of the German Social Democratic Workers Party in the Czechoslovak Republic (DSAP).
[4][5] In contrast to his peers, Čermak was the sole member of the 1920s DSAP leadership that hailed from a major city (having been born in Vienna).