This study analyzes the contract dispute between the Ethiopian government and POLY-GCL Petroleum Group Holdings Limited from the perspective of international business law and investment arbitration. The conflict originated from POLY-GCL’s systematic failure to fulfill its obligations under the Production Sharing Agreements (PSAs) signed in 2013, including repeated financial defaults (such as unpaid annual contributions exceeding USD 1.7 million and failure to register 30% equity capital by the June 2022 deadline), operational delays in developing the Calub and Hilala gas fields in the Ogaden Basin, and inadequate social and environmental compliance that triggered health concerns in local communities. These breaches prompted multiple formal notices from Ethiopian authorities, culminating in the contract termination in September 2022 due to the company’s financial and organizational inability (Endale, 2024; Maasho, 2015). Using a qualitative descriptive-analytical approach, this research examines the root causes of the dispute, the application of core principles such as pacta sunt servanda and good faith, and the effectiveness of the multi-tiered dispute resolution mechanisms involving bilateral negotiations, ICC mediation, and ICSID arbitration. The case illustrates the tension between Ethiopia’s sovereign right to regulate its energy sector for sustainable development and the protection of foreign investors’ legitimate expectations amid evolving regulations, including the 2021 Arbitration Proclamation No. 1237/2021. Findings highlight the importance of stabilization clauses, stakeholder consultation, and thorough risk assessment in long-term energy contracts, offering valuable lessons for balancing investor protection with national developmental priorities in developing countries