This important international agreement provides for the exchange of logistical support, supplies and services on a reimbursable basis. It focuses on logistical support. The agreement does not oblige a country to take military action. Cross-service agreements with authorized countries and international organizations provide for the reciprocal provision of LSSS with the armed forces of that country or international organization. The Secretary of Defense must consult with the Secretary of State and inform the U.S. Senate Armed Services and Foreign Relations Committees and the U.S. House of Representatives Armed Services and International Relations Committees 30 days in advance before designating non-NATO countries as authorized to enter into service agreements. The Acquisition and Cross-Servicing Agreement (ACSA) is negotiated on a bilateral basis between the United States and its NATO allies or coalition partners, which allow U.S. forces to exchange the most common types of support, including food, fuel, transportation, ammunition, and equipment. The agreement in no way obliges a country to act militarily. The ESAs also exist between third countries. Japan and South Korea have both formed ACSA with countries other than the United States. .
As of October 2003, the United States has had ACSAs with 76 countries, including most NATO countries, as well as the NATO Maintenance and Supply Agency (NAMSA), NATO Allied Command and SHAPE. At that time, there were seven ACSAs awaiting final signature by the country and the corresponding combat commander. As of mid-2004, the United States had 76 ACSAs with coalition members, allies, and other organizations around the world. DOD components can use pure acquisition authorization to acquire logistics support, supplies and services (LSSS) from a country that is not a member of NATO if it meets one or more of the following criteria: (1) Does it have a defense alliance with the United States. (2) Authorizes the deployment of members of U.S. forces or the landing of U.S. Navy ships in such a country. (3) Has agreed to preposition American equipment in such a country. (4) Serves as a host country for U.S. forces during exercises or authorizes other U.S. military operations in such a country.
The CASA Act (formerly known as the Nato Mutual Support Act) was passed to facilitate the exchange of logistical support, supplies and services between the United States and other NATO forces.