Saudi Arabia and the UAE, once close allies, have seen their relationship evolve from a unified front against Islamist movements and joint military actions in Yemen to increasing economic rivalry and diplomatic divergence. Key moments include their coordinated efforts in Bahrain and Egypt, the Yemen intervention, the Qatar boycott, and differing approaches to normalizing ties with Israel. Recent tensions highlight economic competition, particularly concerning regional headquarters and trade, alongside disagreements within OPEC and differing stances in Sudan's conflict.