Near the end of the Civil War, the Confederates in desperation were planning to arm black men to fight for the Confederacy (in return for freedom). The war ended before the plan could be put into effect, but people have speculated that if the blacks had been given weapons they might have used them against the Confederate Army.
I don't know whether the Chechen situation is comparable. Certainly a lot of Chechens have reason for anti-Russian sentiments.