1. Introduction. – 2. The Rule of Law. – 2.1. The Right to Have a Fair Trial Under International Law. – 3. Case Studies. – 3.1. The International Criminal Court for the Former Yugoslavia (ICTY). – 3.2. The Iraqi High Tribunal (IHT). – 4. International Law and Comparison of Al-Majid and Mladic. – 4.1. The Weakness of the International Rule of Law in the Ukraine War. – 5. Challenges and the Solution to Unify the Rules Governing the Trial of Grave International Crimes. – 5.1. The ICC Statute and its Challenges. – 6. Conclusions.