While NATO takes all the spotlight, a very major real issue for Russia is that Ukraine started to develop significant partnerships, including military, with Turkey, a centuries old major enemy and competitor of Russia. Turkey has tremendously grown its power in the region in the recent decade (in not a small part because of its very successful drone program). Turkey was a military partner of Georgia back in 2008, though it wasn't great success, yet Georgia has historically been a Russian ally, so it was still a significant achievement for Turkey against Russia. The Syria, Libya and topping all that Azerbaijan were major wins of Turkey against Russia. Turkey is building a regional Muslim states coalition, and in the recent Kyrgyzstan/Tajikistan conflict Turkey provided the drones to the Kyrgyzstan while also played the peace maker role, achieving another successful push against Russian interests. Kazakhstan seems to be a next target there. Yet all that pale when compared to the Turkey's win (crossing into near-future real threat territory) against Russia what the Ukraine/Turkey tight partnership is (there is even some indications that they started talking about nuclear weapons development collaboration - while not much probable to result in any real nukes in any observable future, it just illustrates the degree and direction of the partnership development).