By the end of 1987, Iraq possessed 5,550 tanks (outnumbering the Iranians six to one) and 900 fighter aircraft (outnumbering the Iranians ten to one). After Operation Karbala-5, Iraq only had 100 qualified fighter pilots remaining; therefore, Iraq began to invest in recruiting foreign pilots from countries such as Belgium, South Africa, Pakistan, East Germany and the Soviet Union. They replenished their manpower by integrating volunteers from other Arab countries into their army. Iraq also became self-sufficient in chemical weapons and some conventional ones and received much equipment from abroad. Foreign support helped Iraq bypass its economic troubles and massive debt to continue the war and increase the size of its military.