USSR supported Egypt because they were doing all they could to weaken Western Europe.

America supported Egypt because Eisenhower thought he could get Nasser (and the rest of subsequently decolonized Africa) on America's side. The concern was that Britain and France's actions could strengthen Soviet links with liberation movements, which were already fully aligned with the Soviets. It was the first of the typical American cuckery we know today- betraying our own people in the hope our enemies will take our side. I really can't give a coherent explanation for why we did this pants-on-head retarded move.

This caused the collapse of the British Empire, and a pretty immediate end to colonies in general. The first major casualty was the Belgian Congo, which was actually prospering during the 1950s and creating a Black middle class, and opportunities for the native Blacks while still protecting Whites as well. As soon as Belgium pulled out, the Whites were killed, and the country fell into civil war. Whites were killed across all of "decolonized" Africa, as "decolonization" means Whites who can afford to leave do so, and those who cannot afford to leave get killed.