Later Yahya Khan, as Deputy Chief of General Staff, was selected to head the army's planning board set up by Ayub Khan to modernize the Pakistan Army in 1954–57. Yahya also performed the duties of Chief of General Staff from 1958 to 1962 from where he went on to command two infantry divisions from 1962 to 1965 including one in East Pakistan. Yahya also renamed the Command and Staff College from 'Army Staff College' in Quetta, Balochistan. He played a pivotal role in sustaining the support for President Ayub Khan's campaign in the 1965 presidential elections against Fatima Jinnah. He was made GOC of 7th Infantry Division of Pakistan Army, which he commanded during the 1965 war with India. At this assignment, he was not instrumental in planning and executing the military infiltration operation, the "Grand Slam", which failed miserably due to General Yahya's delay owing to change of command decision, the Indian Army crossed the intentional border and made a beeline for Lahore.