Nwankwo was born in Ajalli, Anambra State. He completed his collegiate degree from Eastern Menonnite University in 1966 and then continued further studies at Duquesne University where he obtained a master's degree. Upon completion of his graduate degree, he briefly worked for Gulf Oil as a consultant. At the onset of the Civil War , he returned to Nigeria where he joined the staff of the propaganda office of Biafra where he also edited a weekly newsletter.