He was reinstated with the rank of Colonel and served as the Principle Staff Officer to Brigadier T. I. Weeratunga as he returned to Jaffna in June 1981 as Commander, Security Forces - Jaffna to subdue the Tamil militant groups operating there. In 1983, Balthazar took over as Commander, Security Forces - Jaffna with the rank of Brigadier. As Commander, Security Forces - Jaffna, he had the Army's Task Force 4 Northern and all armed forces units in the province under his command. He initiated military operations to subdue to Tamil militancy taking form in Jaffna in 1983. He was successful in killing Tamil militant leader Charles Lucas Anthony aka Seelan on 15 July 1983. He attempted to raid Tamil militant leader Sellakili's hideout on 24 July 1983. However, Sellakili ambushed one of Balthazar's routine patrols Four Four Bravo killing thirteen soldiers. This incident sparked the Black July riots and is considered to be the start of the Sri Lankan Civil War. He was succeeded by Brigadier Nalin Seneviratne. He served as Chief of Staff of the Army under General Seneviratne during the Vadamarachchi Operation.