U.S. Marines of 2nd Battalion, 23rd Marine Regiment, advance on an objective during training with U.S. Navy Riverines at 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.