In 1969, President Yahya Khan decided to make administrative changes in the army by appointing the Gen. Abdul Hamid Khan as the Army Chief of Staff (ACOS) of the Pakistan Army, who centralized the chain of command in Rawalpindi in a headquarters known as "High Command". From 1967–69, a series of major military exercises was conducted by infantry units on East Pakistan's border with India. In 1970, the Pakistan army's military mission in Jordan was reportedly involved in tackling and curbing down the Palestinian infiltration in Jordan. In June 1971, the enlistment in the army had allowed the Army GHQ in Rawalpindi to raise and established the 18th infantry division, stationed in Hyderabad, Sindh, for the defence of from Rahimyar Khan to Rann of Kutch, and reestationed the 23rd infantry division for defending the Chhamb-Dewa Sector.