Meeting with UN Special Envoy for Syria Staffan de Mistura, Russian Foreign Minister Sergey Lavrov urged the international community to get together and decide on a formal list of “legitimate” Syrian rebel organizations before the next round of talks in Vienna.
This might seem an odd request, but since the participants in the last Vienna talks agreed to invite legitimate opposition groups for this round, the lack of identification for who those groups are going to be has made inviting them pretty much impossible.
Russia is keen to hold talks with those factions on its long-standing desire to unify the secular rebels with the Syrian government in a unity faction to fight ISIS and al-Qaeda. Having them invited to the talks would be a big step toward getting them sold on such a plan.
The ambiguity about which rebels are “the good guys” has also complicated the narrative on Russia’s airstrikes in Syria, with the US complaining that everyone Russia attacks who isn’t explicitly ISIS is an unacceptable target. Russia has insisted that many of these targets are al-Qaeda or their allies, and indeed with many of the non-ISIS strikes centering on al-Qaeda territory, there is reason to believe that is often the case.