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.
https://www.nato.int/cps/en/natolive/official_texts_17120.ht...
Talking now: which of the plans we have discussed before are we going to enact? Formal meeting, in that a member state has declared it's intent to bring a topic to the table and that the body is obligated to discuss and determine a course of action - which is allowed to be "no action".
Basically, before now everyone figured out what to do on paper, now the Treaty Organization has to make a decision about next steps.