Note that invoking Article 4 is basically calling a conference among NATO members on a security problem. It’s not a “situation normal” sort of thing, but it’s Article 5 that deals with conflict.

www.nato.int/cps/en/…/official_texts_17120.htm

Article 4

The Parties will consult together whenever, in the opinion of any of them, the territorial integrity, political independence or security of any of the Parties is threatened.

Article 5

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 recognised 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.

Any such armed attack and all measures taken as a result thereof shall immediately be reported to the Security Council. Such measures shall be terminated when the Security Council has taken the measures necessary to restore and maintain international peace and security .

EDIT: Article 4 has been invoked seven times in NATO’s history prior to this, mostly by Turkey:

cepa.org/…/a-neglected-younger-sibling-natos-arti…