Complex sentence: Amer's distinguished career came to a sudden end after Egypt's defeat by Israel in the Six-Day War in June of 1967, and he was relieved of all his posts and forced into early retirement.
Split into simpler sentences: Amer's distinguished career came to a sudden end after Egypt's defeat by Israel in the Six-Day War in June of 1967. He was relieved of all his posts and forced into early retirement.