During the Indonesian National Revolution, Muljadi became a leading figure within the "pemuda" movement in Surakarta, specifically the Barisan Banteng organization which he co-founded with Moewardi. At one point, when a leader for the newly formed People's Security Agency was about to select a commander, Muljadi was nominated as one of six potential candidates, and in a public vote just two voted for him, with most voting for either Sudirman (who won) and Urip Sumohardjo. Due to disputes between the central government and the local militants and authorities in Surakarta, Muljadi alongside other leading figures including Moewardi was briefly arrested in late May 1946. However, large-scale rallies coupled with an ultimatum from Barisan Banteng leader Sudiro who threatened to resign and hence leave the "pemuda" uncontrolled, resulted in Muljadi's release on 31 May. He again was arrested by Dutch authorities after Operation Kraai in February 1949 when he refused to join the Dutch-formed "Islamic Council" for Surakarta.