The Enhanced Defense Cooperation Agreement (EDCA) is a 2014 agreement between the United States and the Philippines intended to bolster the American–Philippine alliance. The agreement allows the United States to rotate troops into the Philippines for extended stays and allows the United States to build and operate facilities on Philippine bases for both American and Philippine forces. The U.S. is not allowed to establish any permanent military bases. The Philippines have personnel access to American ships and planes. This agreement has been the subject of criticism by some leftist groups in the Philippines.

The EDCA is a supplemental agreement to the previous Visiting Forces Agreement. The agreement was signed by Philippine Defense Secretary Voltaire Gazmin and US Ambassador to the Philippines Philip Goldberg in Manila on April 28, 2014, preceding a visit by US President Barack Obama with Philippine President Noynoy Aquino that same day. On January 12, 2016, the Philippine Supreme Court upheld the agreement's constitutionality in a 10–4 vote. On July 26, 2016, the Philippine Supreme Court ruled with finality that the agreement is constitutional.

Evan S. Medeiros, a former U.S. National Security Council's senior director for Asian affairs was quoted in The Washington Post as saying, "This is the most significant defense agreement that we have concluded with the Philippines in decades."

For more than a century, the Philippines has been important to American defense strategy. Currently, the Philippines is a "major non-NATO ally" of the United States.

The US acquired the Philippines from Spain after the Spanish–American War of 1898 and then fought the Philippine–American War of 1899–1902 against Philippine revolutionaries to secure their rule. After both wars, the Philippines was a territory of the United States from 1898 to 1946. The United States granted the Philippines independence in 1946.

The Mutual Defense Treaty was signed in 1951 and ratified in 1952 by the governments of the United States and the Philippines. The purpose of the Treaty was to "strengthen the fabric of peace" in the Pacific, by formally adopting an agreement to defend each other's territory in the case of external attack. In line with this treaty, the United States maintained several military bases in the Philippines, including Subic Bay Naval Base and the Clark Air Base. In 1992, the bases closed after the Philippine Senate rejected, by a close vote, a treaty that would have extended the bases' lease. The treaty was rejected because of US reluctance to set a firm time frame for troop withdrawal and to guarantee that no nuclear weapons would pass through the base.

The Philippines–United States Visiting Forces Agreement (VFA) was signed by the governments of the Philippines and the United States in 1998, and came into effect in 1999. This was the first military agreement since the closing of US bases in 1992. The VFA outlined a set of guidelines for the conduct and protection of American troops visiting the Philippines. The Agreement also stipulated the terms and conditions for American military to pass through or land in Philippine territory. The VFA is a reciprocal agreement in that not only does it outline the guidelines for US troops visiting the Philippines but also for Philippine troops visiting the United States.

The signing of the VFA led to the establishment of annual bilateral military exercises between the US and the Philippine known as Balikatan, as well as a variety of other cooperative measures. The Balikatan training exercises ("shoulder-to-shoulder") are annual military exercises between the U.S. and the Philippines. They are structured to maintain and develop the security relationship between the two countries' armed forces through crisis-action planning, enhanced training to conduct counterterrorism operations, and promoting interoperability of the forces.