What does NATO predict in the event of an attack on an ally country?

Although the origin of the missiles that hit Poland and killed two people has not been confirmed, in case the Russian attack on Poland is confirmed, NATO includes in Article 5 of the Atlantic Alliance Organisation Treaty the so-called collective defence principle.

This is a unique and permanent principle that unites its members and puts a spirit of solidarity in the Alliance.

Article 5 says: <x0 selectees agree that an armed attack against one or more of them, taking place in Europe or North America, will be regarded as an attack directed at all, and, as a result, agree that if such an attack occurs, each one of them, in exercising the right of legitimate individual or collective protection, known by Article 51 of the United Nations Charter, will help Pala or the attacked Pauls, then individually and in accordance with the Pauls, including the use of the armed force to preserve the North Atlantic region of <16).