Post-1967 Nasser purged his inner circle of all potential opposition

Evidence

Whereas previously there was quite considerable scope for argument and criticism in Nasser’s immediate circle, this has now ceased. The President now has his hands directly on the levers of power. Those who disagree with him or oppose his policies in any way, still more those who might conceivably form the nucleus of any kind of opposition group, have been systematically eliminated from positions of authority. They have not as yet been eliminated in any further sense but are still living peacefully in Cairo. They appear, however, to be under strict observation. — Bernard Lewis, From Babel to Dragomans, 1246