The Quadrilateral Security Dialogue (Quad) is an informal strategic forum and inter-governmental security dialogue, not a formal alliance, comprising Australia, India, Japan, and the United States. Its origins trace back to the 2004 Indian Ocean Tsunami, when the four nations formed an ad-hoc "Tsunami Core Group" for humanitarian assistance and disaster relief. The dialogue was first formalized in 2007 by Japanese Prime Minister Shinzo Abe. This initial iteration ceased in 2008 after Australia withdrew, but the Quad was revived in November 2017 at the senior official level.
The Quad's primary mechanism is high-level consultation, operating through regular meetings of Foreign Ministers since 2019 and Annual Quad Leaders' Summits since March 2021. The core objective is to promote a "free, open, prosperous and inclusive Indo-Pacific region" and a rules-based maritime order. The grouping works on diverse areas, including maritime security, climate change, critical and emerging technology, and infrastructure. A key related concept is the joint naval exercise Malabar, which included all four navies in November 2020.
The Quad has recently evolved from a primarily security-focused dialogue to one addressing global public goods, notably through the launch of the Indo-Pacific Maritime Domain Awareness (IPMDA) initiative in 2022 and the Quad Infrastructure Coordination Group. The shift to leader-level summits in 2021 marked a significant change, elevating the forum's political profile while maintaining its informal structure, which lacks a permanent secretariat.