Complex sentence: After the Six-Day War defeat, Egypt needed most of its military budget for acquiring new aircraft and air defenses and so, due to this and the availability of Russian fighters, the Egyptian government terminated the project in 1969.
Split into simpler sentences: After the Six-Day War defeat, Egypt needed most of its money for acquiring new air crafts and air defenses. So due to financial problems and the availability of a greater amount of Russian fighters the Egyptian government terminated the project in 1969.