The correct answer is "there would be wars that the superpowers could not win against a strong nationalist and guerrilla-type opposition."
Wars like the ones in Vietnam and Afghanistan demonstrated that there would be wars that the superpowers could not win against a strong nationalist and guerrilla-type opposition.
And history has shown this on many different occasions, as was teh case of the Vietnam War for the United States, or the invasion of Afghanistan by the Soviet troops in the 1980s, or again, the United States, after 9/11.
Strong nationalist and guerrilla-type opposition are important factors that favor the invaded nations, but another key factor is the geography of the land. This factor was of great advantage to Vietnamese troops in the jungle of Vietnam. American soldiers found it so difficult to establish a terrain dominion in the Vietnam War.
The same happened in the desertic zones of Afghanistan, and even worse the hot weather of the desert. A very difficult condition for foreign troops.