The army made it clear that the only viable line of defence Defending for Tawang would be along the Hathung La ridge .

As part of the exercise Practice , towards the end of the year , the army landed Motion a brigade of troops at Zimithaung , south of Hathung La using its new heavy lift Mi-26 helicopters .

These forces Military_operation occupied Attack the Hathung La , across the Namka Chu from Thag La .