Chechenya once declared independence after the collapse of Soviet Union, while it was not recognized by any state. In terms of war, it would probably not fit in the category anyways since the opposition group no longer has control of Chechenya and without the security force with a stable region under cobtrol to defend it. Therefore, it would fit in the category of conflict, or dispute at its best.
Chechnya declared independence from Russia not the SU, since it was part of Russia not the SU.