Abstract: Based on a series of unprecedented developments, Australia and Japan have greatly enhanced their direct bilateral security ties to forge what they now describe as a “special strategic partnership.” This new form of security alignment is not intended to be a traditional alliance pact, but rather represents a novel and versatile mechanism for diplomatic, security, and economic cooperation. Both states seek to pragmatically advance their national interests in tandem and to multiply their capabilities to meet joint security challenges in the Asia-Pacific. In this case, however, the strength and significance of the strategic partnership is further buttressed as a consequence of their adjunct status as “quasi-allies”—through their independent defense pacts with the U.S.—and their combined participation in the Trilateral Strategic Dialogue.