Mustafa Soepardjo

He was one of the leaders of the 30 September Movement, a group that killed six of the army's top generals and launched a failed coup attempt on 1 October 1965.

Some Soepardjo's military colleagues reported he was resentful over his slow pace of promotion and may have had a grudge against army commander, General Yani, who was one of the 30 September Movement's principal victims.

The fact that the document was written before he was arrested means that there was no chance for the military to influence his testimony unlike those from other generals, which led to many unreliable narratives as most of their stories were either coerced through torture or fabricated by the media.

Many are quick to assume that Soepardjo had a significant role in planning the movement due to the fact that he was the highest ranking officer; however, he confesses in the document that he only arrived in Jakarta three days before the event.

There were plenty of detached spectators of the time who could have given their opinions on the movement, but it is Soepardjo’s additional role as an insider that makes his document reliable.

Furthermore, the fact that the core organizers also trusted Soepardjo to talk to the president on their behalf proves that they believed him to be an essential asset to their plans.

This lack of involvement could have led to unfamiliarity about the movement and the party itself, which does cause some discrepancies in his document, such as the number and purpose of sectors that Jakarta was divided into.

However, Soepardjo’s status as the highest ranking officer and direct contact with the core group of organizers makes this document reliable enough to draw accurate conclusions from.

There was a loose structure in the cooperation between the PKI and the military, and the two groups were constantly arguing over courses of strategic action, which led to moments of indecisiveness during critical points in the movement.

However, Soepardjo later reveals in the document that the PKI was the true body behind the movement, and for that reason, he believes Kamaruzaman Sjam played the leading role.