 In 1992 he was named commander of the operation (dubbed Wedding in Mountains) to seize the strategic town of Shusha, the capture of which in May 1992 marked the first significant military victory by Armenian forces during the Nagorno-Karabakh War.Ter-Tadevosyan is known in Armenia as the "mastermind of Shusha liberation".He participated in the formation of the Armenian armed forces and assisted it to overcome significant challenges before it could emerge as a well-developed institution.