At the height of the Cold War, a Soviet response was necessary to avoid the possibility of a new American fighter gaining a serious technological advantage over existing Soviet fighters, thus the development of a new air superiority fighter became a priority.
A Soviet response was necessary to avoid the possibility of a new American fighter. This was at the height of the Cold War. This new American fighter was gaining a serious technological advantage over existing Soviet fighters. The development of a new air superiority fighter became a priority. This was at the height of the Cold War.