The NATO-Russia threat because of Turkey now

The problem now is that Turkey is a NATO member nation along with the U.S. so if Russia now shoots down a Turkish plane with missiles (might happen now) and Turkey calls upon NATO to defend itself against Russia, this could be a problem. However, Turkey also knows that Russia and U.S. are the most nuclear armed nations likely on earth. I don't think it is really known how many nuclear warheads China actually has. So, because of the nuclear threat even if Turkey called upon NATO for help this could be a problem because of Russia's, the U.S's, Britain's, France's and possibly Germany's nuclear weapons. So, it is possible that NATO might or might not provide military assistance because this goes against Cold War Nuclear weapons protocol to avoid nuking the earth completely out of existence. This gets even further to be a problem because Pakistan IS a nuclear armed nation and is also Sunni like Turkey and might use it's nuclear weapons against Russia in this kind of situation. Then it gets even more complicated because of alliances between China and Russia historically as far back as the Soviet Union and Mao Tse Tung and what China is going to do if the right series of events takes place.

However, I'm sure there are going to be people in all these countries working diligently to prevent such a scenario from taking place.