Playing world-cop for 28 nations of Europe is an expensive proposition. 28 individual trip-wires in Europe is also a dangerous proposition. Let Europe defend itself. Under the present situation, we are both subsidizing and allowing the creeping Islamization, and socialism of Europe. This destructive trend is what NATO and the EU regime is supporting and pursuing right now. This is the new threat. The Soviet Union and its ideology is dead. Time to move your understanding into the future.
I lived in Poland during the days of Solidarnosc' and martial law and visited afterwards when the Wall came down. I know what the Communists can do to a society. Putin is a KGB thug who must be stopped. His seizure of Crimea is an example. If Ukraine had been part of NATO, this would not have happened.
Yes, NATO must share more of the costs of its defense, but walking away by dissolving NATO will create a vacuum of power that will be filled by other, more sinister forces. It will also lessen US influence, which is not a good thing. The West must stand together.
Article 5 of the NATO treaty has only been invoked once, i.e., when the US was attacked on 9/11. This is why NATO was in charge of the effort in Afghanistan.