Summary In April 2023, the Review of European Law published a paper authored by Professor Yumiko Nakanishi at the Graduate School of Law, Hitotsubashi University, titled "The Principle of The Primacy of EU Law and the Right to Request Preliminary Rulings from Domestic Courts." The paper discusses the ruling of the European Court of Justice (ECJ) regarding Poland's challenge to the annulment of the conditionality rules. The rules regarding the EU Recovery plan raised concerns about the mechanism assuming respect for the rule of law. Professor Nakanishi analyzes the judgment as the second chamber ruling establishing a mechanism obligating compliance with the rule of law. She also confirms that this measure is in line with EU law. The ECJ explains that Article 2 of the EU Treaty covers the principle of the rule of law and it relies on it as a legal reasoning. The ECJ also emphasizes the need for measures to protect its value in various situations, stating that EU member states should uphold this value. Professor Nakanishi says this case is significant, revealing the EU's identity for the first time in the judicial field. She also notes that this ruling is essential for developing EU law, facilitating judicial decisions to reaffirm the rule of law.