It's amazing how many people who say "you need to read xxx" have never actually read it...
The Parties agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all and consequently they agree that, if such an armed attack occurs, each of them, in exercise of the right of individual or collective self-defence recognized by Article 51 of the Charter of the United Nations, will assist the Party or Parties so attacked by taking forthwith, individually and in concert with the other Parties, such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area.
Thats from the NATO website. Doesn't say they need to convene, it says that any member is allowed to respond in any manner they deem necessary.
NATO countries have more than 10,000 troops deployed in Poland. The last time Russia played a game of FAFO with the US,it ended poorly. Repeating that with NATO would be infinitely worse.
And no, despite Russian fanboy insistance, the US isn't low on ammo. From the Secretary of the Army's testimony to congress:
“[the Army is] comfortable that the amount of lethal assistance we’ve been providing is not eroding our readiness, but we keep a close eye on that.”
There may be issues with the amount of excess the US has to give away, I'll believe that when I see the US govt stop sending it.