Gandhiji decided to withdraw the Non-Cooperation Movement primarily because it was turning violent, which violated the core principle of non-violence he had established for the movement. The immediate trigger was the Chauri Chaura incident in February 1922, where a peaceful protest turned violent, leading to the burning of a police station and the death of 22 policemen. Gandhi was deeply shocked and believed that the Indian masses were not yet prepared for a disciplined and non-violent mass struggle. Other contributing factors included the loss of relevance of the Khilafat issue, the rise of militancy, violence in various places like the Mopillah revolt in Kerala, and the shift towards class struggles which he did not endorse. Additionally, the British government’s harsh repression and arrests also made continuation difficult. Gandhi's withdrawal was a strategic and moral decision to uphold the ethical foundations of the movement and to prevent it from degenerating into violence and losing popular support.