This report documents war crimes and other human rights violations committed by the Myanmar military as part of a major operation against the ethnic armed group the Arakan Army (AA) since January 2019. The investigation also found evidence of abuses committed by the AA. Based on a field investigation as well as remote interviews, review of satellite imagery, photographs, and videos, the report shows how – less than two years after the Myanmar military’s atrocities against the Rohingya population – the military has engaged in a pattern of unlawful attacks killing and injuring civilians, arbitrary arrests, torture, enforced disappearances, extrajudicial executions, looting, and forced labour. These violations bring in to sharp focus the consequences of ongoing impunity for a military which stands accused of crimes against humanity, war crimes, and genocide. The situation requires an urgent international response, in particular from the UN Security Council. Continued inaction will send a dangerous message to the military that such crimes can continue.