Question: A country's military branch, the equivalent of which in the US contains the Air Defense Artillery, was unprepared for the invasion of Ivo Werner's country. When was the word "Slavs" used in the national anthem of the unprepared country?

Knowledge 1: United States Army
Currently, the army is divided into the Regular Army, the Army Reserve, and the Army National Guard. The army is also divided into major branches such as Air Defense Artillery, Infantry, Aviation, Signal Corps, Corps of Engineers, and Armor. Before 1903 members of the National Guard were considered state soldiers unless federalized (i.e., activated) by the President. Since the Militia Act of 1903 all National Guard soldiers have held dual status: as National Guardsmen under the authority of the governor of their state or territory and, when activated, as a reserve of the U.S. Army under the authority of the President. [SEP] Knowledge 2: Josip Broz Tito
In 1968, Tito offered Czechoslovak leader Alexander Dubček to fly to Prague on three hours notice if Dubček needed help in facing down the Soviets. In April 1969, Tito removed generals Ivan Gošnjak and Rade Hamović in the aftermath of the invasion of Czechoslovakia due to the unpreparedness of the Yugoslav army to respond to a similar invasion of Yugoslavia. [SEP] Knowledge 3: Ivo Werner
Ivo Werner (born 19 August 1960) is a former professional tennis player originally from Czechoslovakia who competed for both his native country as well as West Germany. Werner, who is now a tennis coach, immigrated to West Germany in 1982 and got citizenship two years later. [SEP] Knowledge 4: Slavs
The word "Slavs" was used in the national anthem of the Slovak Republic (1939–1945), Yugoslavia (1943–1992) and the Federal Republic of Yugoslavia (1992–2003), later Serbia and Montenegro (2003–2006).
Knowledge 1: United States Army
Currently, the army is divided into the Regular Army, the Army Reserve, and the Army National Guard. The army is also divided into major branches such as Air Defense Artillery, Infantry, Aviation, Signal Corps, Corps of Engineers, and Armor. Before 1903 members of the National Guard were considered state soldiers unless federalized (i.e., activated) by the President. Since the Militia Act of 1903 all National Guard soldiers have held dual status: as National Guardsmen under the authority of the governor of their state or territory and, when activated, as a reserve of the U.S. Army under the authority of the President. [SEP] Knowledge 2: Josip Broz Tito
In 1968, Tito offered Czechoslovak leader Alexander Dubček to fly to Prague on three hours notice if Dubček needed help in facing down the Soviets. In April 1969, Tito removed generals Ivan Gošnjak and Rade Hamović in the aftermath of the invasion of Czechoslovakia due to the unpreparedness of the Yugoslav army to respond to a similar invasion of Yugoslavia. [SEP] Knowledge 3: Ivo Werner
Ivo Werner (born 19 August 1960) is a former professional tennis player originally from Czechoslovakia who competed for both his native country as well as West Germany. Werner, who is now a tennis coach, immigrated to West Germany in 1982 and got citizenship two years later. [SEP] Knowledge 4: Korean War
A major consideration was the possible Soviet reaction in the event that the US intervened. The Truman administration was fretful that a war in Korea was a diversionary assault that would escalate to a general war in Europe once the United States committed in Korea. At the same time, "[t]here was no suggestion from anyone that the United Nations or the United States could back away from [the conflict]". Yugoslavia–a possible Soviet target because of the Tito-Stalin Split—was vital to the defense of Italy and Greece, and the country was first on the list of the National Security Council's post-North Korea invasion list of "chief danger spots". Truman believed if aggression went unchecked a chain reaction would be initiated that would marginalize the United Nations and encourage Communist aggression elsewhere. The UN Security Council approved the use of force to help the South Koreans and the US immediately began using what air and naval forces that were in the area to that end. The Administration still refrained from committing on the ground because some advisers believed the North Koreans could be stopped by air and naval power alone.
Knowledge 1: United States Army
Currently, the army is divided into the Regular Army, the Army Reserve, and the Army National Guard. The army is also divided into major branches such as Air Defense Artillery, Infantry, Aviation, Signal Corps, Corps of Engineers, and Armor. Before 1903 members of the National Guard were considered state soldiers unless federalized (i.e., activated) by the President. Since the Militia Act of 1903 all National Guard soldiers have held dual status: as National Guardsmen under the authority of the governor of their state or territory and, when activated, as a reserve of the U.S. Army under the authority of the President. [SEP] Knowledge 2: Josip Broz Tito
In 1968, Tito offered Czechoslovak leader Alexander Dubček to fly to Prague on three hours notice if Dubček needed help in facing down the Soviets. In April 1969, Tito removed generals Ivan Gošnjak and Rade Hamović in the aftermath of the invasion of Czechoslovakia due to the unpreparedness of the Yugoslav army to respond to a similar invasion of Yugoslavia. [SEP] Knowledge 3: Slavs
The word "Slavs" was used in the national anthem of the Slovak Republic (1939–1945), Yugoslavia (1943–1992) and the Federal Republic of Yugoslavia (1992–2003), later Serbia and Montenegro (2003–2006). [SEP] Knowledge 4: Korean War
A major consideration was the possible Soviet reaction in the event that the US intervened. The Truman administration was fretful that a war in Korea was a diversionary assault that would escalate to a general war in Europe once the United States committed in Korea. At the same time, "[t]here was no suggestion from anyone that the United Nations or the United States could back away from [the conflict]". Yugoslavia–a possible Soviet target because of the Tito-Stalin Split—was vital to the defense of Italy and Greece, and the country was first on the list of the National Security Council's post-North Korea invasion list of "chief danger spots". Truman believed if aggression went unchecked a chain reaction would be initiated that would marginalize the United Nations and encourage Communist aggression elsewhere. The UN Security Council approved the use of force to help the South Koreans and the US immediately began using what air and naval forces that were in the area to that end. The Administration still refrained from committing on the ground because some advisers believed the North Koreans could be stopped by air and naval power alone.

Answer: 1943–1992