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Each Party 【recognizes that [{an armed attack against either Party (in the territories under the administration of Japan)} would be dangerous to its own peace and safety]】 and 【declares that {it would act to meet the common danger (in accordance with its constitutional provisions and processes)}】.
it=Each Party=US and Japan
(Any such armed attack) and (all measures taken as a result thereof) shall be immediately reported to (the Security Council of the United Nations) (in accordance with the provisions of Article 51 of the Charter). Such measures shall be terminated {when the Security Council has taken the measures (necessary to restore and maintain international peace and security)}.