Investor-State Dispute Settlement (ISDS) is the most controversial yet most effective protection mechanism in international investment law. This article examines the ICSID Convention, Türkiye's bilateral investment treaty network, the Energy Charter Treaty, and the major investment arbitration cases to which Türkiye has been a party.
Investor-State Dispute Settlement (ISDS), as one of the fundamental pillars of international investment law, grants foreign investors the right to directly bring international arbitration claims against measures taken by the host state. This system, operating within the framework of the ICSID Convention (1965), bilateral investment treaties (BITs), and multilateral investment agreements, provides legal guarantees to foreign investments while also constraining the regulatory autonomy of states. Türkiye plays an active role in this system both as a host state and as a state of investor nationality.
1. The ICSID Convention and Türkiye's Party Status
The Convention on the Settlement of Investment Disputes between States and Nationals of Other States (ICSID Convention) was signed in Washington in 1965 and established the International Centre for Settlement of Investment Disputes (ICSID) within the World Bank. Türkiye became a party to the Convention in 1989 and has since been a party to numerous investment arbitration cases. With its sui generis structure — mechanism independent of contracting states, direct enforceability of awards, and special annulment procedure — ICSID is the de facto standard institution in investment arbitration.
2. Türkiye's Bilateral Investment Treaty (BIT) Network
Türkiye has concluded bilateral investment treaties (BITs) with more than 80 states, the vast majority of which are in force. Turkish BITs typically include broad definitions of investment, fair and equitable treatment standards, full protection and security, compensation for expropriation, free transfer provisions, and ISDS clauses. When an investor alleges a breach of treaty-protected rights, it may bring an arbitration claim against the host state under the arbitration procedure designated in the treaty. The standards of the Vienna Convention on the Law of Treaties (VCLT) play a decisive role in the interpretation of treaties.
3. The Energy Charter Treaty and the Modernisation Process
The Energy Charter Treaty (ECT), signed in 1994, provides a special protection regime for investments in the energy sector. Türkiye is one of the signatory states to the ECT and has been involved in cases under the treaty both as a claimant and respondent. Article 26 of the ECT grants investors the right to direct arbitration, and the protection standards it covers create a broader framework than BITs. Within the ECT modernisation process, certain European states have moved to withdraw from the treaty, a development that has had significant effects on intra-EU investment disputes. The CJEU's Achmea and Komstroy judgments have established a new paradigm regarding the validity of intra-EU arbitration clauses.
4. Investment Arbitration Cases Involving Türkiye
Türkiye has been the respondent in numerous investment arbitration cases under ICSID and UNCITRAL rules. Cases such as PSEG v. Türkiye, Libananco v. Türkiye, Cementownia v. Türkiye, Tulip Real Estate v. Türkiye, and Saba Fakes v. Türkiye have tested the limits of Türkiye's investment protection obligations in the energy, real estate, finance, and telecom sectors. These cases have addressed fundamental issues such as expropriation claims, violations of the fair and equitable treatment standard, the application of the national treatment principle, and the impact of state regulatory measures on investments. Turkish investors have also become regional players through cases initiated against states such as Turkmenistan, Libya, and Saudi Arabia.
5. Challenges to Arbitral Jurisdiction: Definitions of Investment, Investor, and Dispute
One of the most critical stages in investment arbitration cases is the tribunal's jurisdictional determination. Under Article 25 of the ICSID Convention, the dispute must "arise out of an investment." The criterion known in ICSID jurisprudence as the Salini test — the duration of the investment, transfer of resources, assumption of risk, and contribution to the economic development of the host state — has become a decisive standard in defining investment. The nationality of the "investor," analysis of the control structure, and whether the dispute qualifies as a "legal dispute arising directly out of an investment" are also subject to detailed examination within the scope of jurisdictional determination.
6. Annulment and Enforcement: Annulment Procedure and the New York Convention
ICSID awards are subject to the Convention's sui generis annulment mechanism and may be annulled on limited grounds by ad hoc committees (Article 52). Enforcement of ICSID awards is, under Article 54 of the Convention, directly enforceable in contracting states as if it were a final domestic court judgment. Investment arbitration awards rendered outside the ICSID framework (under UNCITRAL, SCC, or ICC rules) are enforced under the 1958 New York Convention. Türkiye has been a party to the New York Convention since 1992.
7. Looking Ahead and Practical Recommendations
The investment arbitration system is currently subject to various reform discussions. The Multilateral Investment Court (MIC) project proposed by the EU is the most comprehensive reform proposal aimed at replacing the existing ad hoc arbitration system with a permanent court structure. The ISDS reform negotiations conducted within UNCITRAL Working Group III are also shaping the future of the system. Practical recommendations for foreign investors and states include screening the BIT network of the country in which investment is made, obtaining pre-dispute advisory services, evaluating negotiation and settlement mechanisms, and meticulously collecting evidence in the pre-arbitration period. For advisory services on investment arbitration and international investment protection, please contact us at info@guzeloglu.legal.