Together, we are the United Nations
Gunulfr ok Øgotr ok Aslakr ok Rolfr resþu sten þænsi æftir Ful, felaga sin, ær warþ ... døþr, þa kunungar barþusk.
1-Can one play a second cc card on a combat?
Yes, most certainly.
2-If possible, does this play negate the second attack? (The second attack is in Azerbijan)
I would say it could negate the second attack (assuming the Russians withdraw out of reach of the second stack). Just because Enver is a bad general doesn't mean the Stavka can't panic