Though an exercise's primary officially defined purpose is to train U.S. forces, foreign militaries often receive training as well. The U.S. Southern Command (Southcom), the joint military body responsible for Latin America and the Caribbean, makes interaction with foreign militaries a high priority; as a result, its exercises in the region frequently include other armed forces in some capacity, whether as co-participants, observers, or perimeter guards. Other militaries' participation results in some transfer of skills and knowledge, making foreign military training a key secondary outcome of exercises.

Other objectives of U.S. military exercises in the region, according to a National Defense University (NDU) publication, include:

1. Fostering interoperability between U.S. forces and potential military partners;
   ["Interoperability" means "the ability of systems, units or forces to provide services to and accept services from other systems, units or forces, and to use the services so exchanged to enable them to operate effectively together."¹]
2. Building interpersonal contacts and force collaboration;
3. Serving as confidence-building measures among neighboring states; and
4. When an exercise involves construction, providing "a tangible example of U.S. commitment to a country" and facilitating "subsequent U.S. deployments in response to regional crises."²

Exercises, the NDU notes, "tend to be expensive and often, because of their strategic importance, drain funding intended for other defense programs."

Within its area of operation, Southcom divides its exercises among three categories: operational, foreign military interaction and engineer exercises.

1. Operational exercises are carried out with specific threats or scenarios in mind. Participants follow action plans devised for dealing with these scenarios. Operational exercises seek to gauge a contingency plan's effectiveness and the participants' ability to carry it out. In recent years, the U.S. military has rarely performed operational exercises in cooperation with foreign units.

In Latin America and the Caribbean, according to a May 1997 Southcom document, operational exercise scenarios might include:

• Defense of the Panama Canal;
• Combating terrorism;
• Noncombatant evacuation operations;
• Peace enforcement operations;
• Peacekeeping operations;
• Counterdrug;
• Counterterrorism;
• Haiti;
• Cuba;
• Humanitarian assistance / disaster relief; or
• Migrant operations.³

Examples of recent operational exercises include:

• Blazon Resolve (Scenario: Counter-terrorism) Honduras
• Blue Advance
• Ellipse Echo
• Fuertes Defensas (Panama Canal Defense)
• Rescue Forces / Fuerzas de Rescate
• Non-Combatant Evacuation (NEO) Forces / Fuerzas de Evacuación⁴

2. Foreign military interaction (FMI) exercises, also referred to as multinational exercises, are carried out jointly with other militaries, normally several at a time. Southcom has phased out one-on-one exercises, as its 1999 "Posture Statement" explains:

In the past, we conducted a greater number of exercises, but many of them were bilateral. Today, as a matter of policy, we conduct no bilateral exercises. Our objective is to migrate from regional, to inter-regional exercises, and ultimately to hemispheric efforts for challenges such as narcotrafficking and terrorism.⁵

Multilateral exercises in the region no longer involve combat scenarios, according to a Southcom document.

Beginning in 1995, Southcom’s exercises shifted from bilateral events featuring conventional combat scenarios to multilateral exercises focusing on peacekeeping, humanitarian assistance, counter narco-trafficking, and other more appropriate post-Cold War missions.⁶

The Distinguished Visitor Program, a component of many Southcom FMI exercises, invites host-region government, business and military leaders "to observe an exercise, sit as panel members in special exercise seminars and participate in exercise After Action Reviews."⁷

Foreign military interaction exercises normally take one of three forms:

• Field Training Exercises (FTX): A "Field Training Exercise" simulates actual operations "in the field," focusing more on improvement of skills than on the making of command decisions.
• Command Post Exercises (CPX): A "Command Post Exercise," which often relies on a computer simulation, guides decisionmakers through a hypothetical scenario. A CPX normally takes place in one central location, such as a military headquarters.
• Seminars: Participants learn and exchange skills through lectures and classroom-style discussion. Southcom appears to be making increasing use of the seminar format.

Examples of multinational exercises include:

1. Peacekeeping

• Fuerzas Aliadas Peacekeeping
• Fuerzas Unidas Peacekeeping
• Tradewinds
• Fuerzas Unidas Cabanas

2. Humanitarian

• Fuerzas Aliadas Humanitarian
• New Horizons / Nuevos Horizontes

3. Counterdrug

• Fuerzas Unidas Counterdrug
• Fuerzas Aliadas Riverine
• Fairwinds

4. Other

• UNITAS

3. Engineer exercises involve construction of basic infrastructure and provision of medical, dental and veterinary services. As U.S. law forbids the military from carrying out most civilian construction or health missions on U.S. soil, engineer exercises give U.S. forces a chance to learn and practice these skills on foreign soil without similar restrictions.

By providing basic services to populations in developing countries, these exercises also include a major humanitarian and civic assistance component. Participating military personnel normally leave behind new or renovated schools, wells, clinics, roads or bridges, while offering medical, dental or veterinary care at no cost to civilian populations.

Critics of these exercises express concern that they encourage military involvement in activities that are non-military in nature, inviting an expansion of military roles beyond that normally seen in well-established democracies.

Engineer exercises can be performed with or without host-nation military participation. In most cases, host-country security forces either participate or provide security around the perimeter of the exercise area.

Examples of engineer exercises include:

• Humanitarian and civic assistance exercises
  • New Horizons / Nuevos Horizontes
  • Medical / dental / veterinary support deployments
• Skills exchange exercises

Section 2010 of Title 10, U.S. Code mandates that, by March 1 of each year, the Secretary of Defense submit a report containing the following information about the past fiscal year:

1. A list of the developing countries which the United States reimbursed for incremental expenses incurred while participating in a military exercise; and
2. The amount each country was reimbursed.

"Incremental expenses," according to section 2010, means "the reasonable and proper cost of the goods and services that are consumed by a developing country as a direct result of that country’s participation in a bilateral or multilateral military exercise with the United States." These may include rations, fuel, training ammunition and transportation. Incremental expenses do not include pay, allowances, and other normal costs.