mission Regional Security Officer (RSO) The DSS presence overseas is led at each embassy by a DSS Special Agent known as a Regional Security Officer (RSO), who is in charge of a Regional Security Office and serves as the senior law enforcement advisor and security attaché to the U.S. Ambassador. Like all members of the Foreign Service, DSS agents cannot remain posted in the U.S. for more than six consecutive years and must eventually be assigned to an overseas post. Once assigned overseas, a DSS agent will typically serve first as a Special Agent called an Assistant Regional Security Officer (ARSO) in a Regional Security Office. Agents who enjoy the overseas lifestyle will try to get a second tour in a Special Agent slot at a large embassy, or possibly serve as a Regional Security Officer (RSO) at a small post or as a Deputy Regional Security Officer (DRSO) at a medium-sized post. Usually after two back-to-back overseas tours, agents will be encouraged to return to the U.S. and serve in a headquarters position before returning overseas as a Regional Security Officer. DSS has been expanding its criminal role overseas and now has many overseas fraud investigator positions. These positions are referred to as “I” positions – as in “Investigator” – and they are commonly referred to as ARSO-Is. These agents work out of the consular sections of embassies and consulates instead of the Regional Security Offices. The performance of these agents is rated by the RSO or the Deputy RSO and is reviewed by the Consul General. There are several other overseas positions filled by DSS agents. At new building construction sites, agents will serve as the Site Security Manager (SSM) where they will supervise the overall security of the new building including the Construction Security Technicians (CST) and Cleared American Guards (CAG). For construction at posts where there is a critical counterintelligence (CI) threat, agents will also serve as CI investigators dedicated to preventing compromise of the most sensitive spaces within the new embassy. It is common for domestically assigned DS agents to serve temporary duty (TDY) at Embassies overseas. Such duty can range from various types of protection duties to RSO support or security training for an overseas post, and may last for as little as a few days to multiple months. DSS agents have often found themselves in harm's way, with four agents and 28 contract