Paraguay has partnered with Argentina, Brazil, and the United States in regional anti-terrorism and anti-narcotics efforts. In July 2005, U.S. special forces began arriving at Paraguay's Mariscal Estigarribia air base to support joint training and humanitarian operations In 2019, Asuncion hosted the first meeting of the Regional Security Mechanism (RSM), which promotes cooperation between Paraguay, Argentina, Brazil, and the U.S. in addressing transnational crime and terrorism in the "triple frontier" region.