The ANZUS Treaty: US–Australia–New Zealand Security Pact (1951–Present)

The alliance is the ANZUS Treaty — signed 1 September 1951, entered force 29 April 1952.

Core Provisions

• Article II: Consult if territorial integrity, political independence, or security threatened in Pacific.
• Article III: Maintain/develop individual/collective defense capacity.
• Article IV: Armed attack on any party in Pacific area → each acts to meet common danger (per constitutional processes).
• Article V: Definition of "Pacific area" — includes parties' territories, island possessions, armed forces, vessels, aircraft in Pacific.

The New Zealand Rupture (1985–Present)

• 1984: Labour Govt (Lange) bans nuclear-armed/powered ships from NZ ports.
• 1986: US suspends ANZUS obligations to NZ (no port access for USN).
• Result: Treaty remains in force, but US–NZ security cooperation frozen. AUS–US bilateral alliance continues. NZ–US: intelligence (Five Eyes), training, but no mutual defense guarantee.

Current State

• US–Australia: Deepest military integration (Pine Gap, Darwin Marines, joint exercises, AUKUS submarines).
• Australia–NZ: Closer Defence Relations (CDR), joint exercises, Five Eyes.
• US–NZ: 2012 Washington Declaration (strategic partnership), 2016 Wellington Declaration — but no ANZUS restoration.

Why It Matters

ANZUS anchored Cold War Pacific strategy. Today, it's the skeleton for US–Australia alignment against China — with NZ partially outside the security umbrella but inside the intelligence tent.