WTF does being a founding member have to do with anything?
Well, for one, it is in the charter. Second, the security council, which includes Russia, is unsurprisingly split. Third, after magically getting past the security council, they would first have to kick Turkey out, while NATO does the same, same for the EU (not quite yet a full member,but the EU would have to act). Since our mentally ill president, just a couple days ago, sold the Kurds to slaughter on 6 hours notice, all of this could not have happened already.