As President, Sukarno moved closer to the Indonesian Communist Party (PKI) in the early '60s. Yani, who was very anti-communist, became very wary of the PKI, especially after the party expressed its support for the establishment of a fifth force (other than the four armed forces and police) and Sukarno tried to impose Nasakom (Nationalism-Religion-Communism) doctrine in the military. Both Yani and Nasution procrastinated when ordered by Soekarno on 31 May 1965 to prepare a plan to arm the people.
In the early hours of October 1, 1965, the September 30th Movement attempted to kidnap seven members of the Army's general staff. A team of about 200 people surrounded Yani's house on Jalan Latuhahary no. 6 on the outskirts of Jakarta Menteng, Central Jakarta. Usually Yani has eleven soldiers guarding his house. His wife later reported that a week earlier an additional six people were assigned to him. These men came from the command of Colonel Latief, known to Yani, was one of the main gangs in the September 30th Movement. According to Yani's wife, those extra people did not appear to be on duty that night. Yani and her children are sleeping in her house while his wife is out celebrating her birthday with a group of friends and relatives. He then recounts that when he left home around 11:00, he saw someone sitting across the street as if keeping the house under the watchdog. He did not think anything at the time, but after that morning's event he wondered differently. Also, from about 9 o'clock on the night of September 30th there are a number of home phone calls at intervals, which when answered will meet with silence or a voice will ask what time it is. The call continued until about 1.00am and Mrs. Yani said she had a hunch something was wrong that night.