The Main Intelligence Directorate (GRU) is the largest foreign intelligence agency operated by the Russian government, founded on 21 October 1918 as the Bolsheviks' "Registration Agency" (RU). Leon Trotsky created the RU as a military intelligence agency, and the Cheka infiltrated the GRU in 1919, leading to a rivalry akin to that of the CIA and FBI in the United States. In 1942, the GRU of the Soviet Union was created, and it would remain in existence even after the end of the Cold War; the GRU of the Russian Federation was founded on 7 May 1992. The GRU came to command the 25,000-strong GRU Spetsnaz in 1997, and the GRU was involved in espionage overseas, including assisting the Syrian government during the Syrian Civil War and tampering with the 2016 US presidential election in favor of pro-Russia candidate Donald Trump. By May 2023, US intelligence estimated that the GRU Spetsnaz had suffered 90-95% losses during the 2022 Russian invasion of Ukraine.