U.S. Marines cover each other during a simulated medical evacuation as part of a riverine training scenario during UNITAS-Partnership of the Americas 2012 Sept. 8. UNITAS-Partnership of the Americas gives the participating troops from Brazil, Canada, Chile, Colombia, Ecuador, Mexico, Paraguay, Peru, the United States and Uruguay an opportunity to exercise critical thinking based on realistic scenarios, reinforce essential tactics and techniques and build on a strong foundation of professional cooperation.