This is Article 4 of the North Atlantic Treaty (Poland is a NATO member). “The Parties shall consult each other when the territorial integrity, political independence or security of either Party is threatened.”. Article 5 provides for a mechanism of mutual assistance in the event of an attack and includes: “The Parties agree that an armed attack against one or more persons in Europe or North America shall be regarded as an attack on all Parties, and accordingly, in the event of such an attack, they each agree to exercise the right of individual or collective self-defence recognized in Article 51 of the Charter of the United Nations, by the Party or Parties so attacked and by immediate and individual agreement with the other Parties. It shall assist by taking such action as it deems necessary, including the use of armed forces to restore and ensure security in the North Atlantic region. Any such armed attack and any consequential action shall be immediately brought to the attention of the Security Council. These actions shall cease when the Security Council takes such action as may be necessary to restore and maintain international peace and security.»