Служба безпеки України (СБУ) is the main security agency of Ukraine, responsible for protecting the state from internal and external threats. It was established in 1991 after Ukraine gained independence from the Soviet Union. The SBU's primary functions include counterintelligence, counterterrorism, and the protection of state secrets. The agency also investigates serious crimes, such as corruption and organized crime, and works to ensure national security. The SBU collaborates with other law enforcement agencies and international organizations to address security challenges, particularly in the context of ongoing conflicts involving Russia and issues related to Ukrainian sovereignty.