The Third Beirut Crisis was a small-scale conflict on Earth that saw combat aircraft of the United States and Soviet Union engage each other, caused when both powers were drawn into direct involvement in a conflict between their respective Middle Eastern clients. Through intensive diplomatic efforts, the crisis was defused and did not lead to an all-out war or the use of nuclear weapons. Nevertheless, it did contribute to a lasting exacerbation of their relationship and the prolongation of the Cold War up to the time when both sent their expeditions to Minerva.