President Joe Biden hosted the fourth in-person Quad Leaders Summit in Wilmington, Delaware, on Saturday to discuss a range of topics concerning the four nations, including ways to enforce international law in the waterways of the Indo-Pacific.

Ahead of the summit, the White House announced the Quad partners will soon begin their first joint coastguard exercises that will become a rotational training effort. The United States will lead the first round of the joint training, with Australian, Japanese, and Indian personnel coming aboard a U.S. Coast Guard vessel to pick up and exchange skills.

The White House announced the Quad will also expand its existing Indo-Pacific Partnership for Maritime Domain Awareness (IPMDA) initiative. The IPMDA aims to increase transparency about maritime activity in the region and how nations may be asserting their various claims in the Indo-Pacific waterways, providing awareness not only to the Quad members but also other regional partner nations.

The four-way Quad partnership has the potential to serve as a check on the expansionist pursuits of the Chinese Communist Party, but its members have avoided announcing any quadrilateral military alliance that could one day face war with the communist party if it moves to enforce its model of governance in the region. The United States has instead pursued separate bilateral alliances and security partnerships more specifically positioned to respond to hostilities in the region.

US–Australia

Biden met with Australian Prime Minister Anthony Albanese on Friday evening for a bilateral discussion ahead of the main Quad meeting. In their post-meeting readouts, Biden and Albanese both emphasized the centrality of the shared values of the U.S.–Australia alliance to relations between their two countries. They both alluded to a "depth of cooperation" on defense and security, economic ties, and climate and clean energy initiatives.

According to the White House readout, the two leaders discussed their support for maintaining peace throughout the Taiwan Strait. The Taiwanese people govern themselves independently of the Chinese mainland. But the People's Republic of China considers the island, also known as the Republic of China, as part of its territory despite there being no formal peace treaty to end the Chinese civil war in 1949. Since the 1970s, the United States has favored a strategically ambiguous status quo on the question of who should control Taiwan.