Russian Cossacks Chechen retaliation, why Chechens are afraid of Cossacks

Cossacks have a tradition of soldiering, the folk style is tough, most of the middle-aged Cossack males are veterans, the battlefield these veterans are quite difficult to deal with. When the first Chechen war, the government forces are new recruits, and Chechnya has a lot of old Soviet troops, veterans abuse new recruits, the more abuse the happier. Waiting for the Cossacks to take revenge, that is the duel between the veterans, the Cossack side and the federal government's support, so the Chechens are very afraid of those Cossacks.