During which conflict was the Avenger system primarily used?

The Avenger system was primarily used during the Gulf War, which took place from 1990 to 1991. This conflict marked the first significant deployment of the Avenger in combat, showcasing its capabilities as a short-range air defense system designed to protect ground forces against aerial threats such as helicopters and low-flying aircraft. The Avenger, equipped with Stinger missiles, was lauded for its mobility and effectiveness in various battlefield environments during this conflict.

In comparison, the other conflicts listed did not see the operational use of the Avenger system in the same capacity. While the Vietnam War and the Korean War involved multiple air defense systems, the Avenger was not yet developed or deployed during those times. Similarly, although Operation Enduring Freedom involved a variety of military hardware, the Avenger's first significant deployment in combat scenarios was during the Gulf War, making it the correct answer to this question.