Whither Pak-Afghan Defence Cooperation has been commissioned by PILDAT to serve as a background paper for the Parliamentary Dialogue between Pakistan-Afghanistan Defence Committees being facilitated by PILDAT in Kabul, Afghanistan. The paper has been authored by Maj. Gen. (Retd.) Athar Abbas, former Director General Inter-Services Public Relations and covers the status of defence relations between Pakistan and Afghanistan. This paper covers the genesis of Pak-Afghan disputes, state of defence cooperation between Pakistan and Afghanistan and potential for improvement, the state of armed forces, causes of friction and concerns, the challenges ahead and the way forward.