There's a difference between member states pulling their weight and the org itself pulling itself together to behave as a coherent entity. If Turkey (or any member) decides to veto or drags its feet prevent any action at all from occurring, it doesn't matter. In the mean time, the aggressor is taking advantage and ransacking its way through Europe. The whole time, the individual members are waiting for the Yanks to get off their arses to unilaterally come to action. Then they can later point at how the Yanks are always doing things unilaterally and turn them into the whipping boy.