Invoking Sovereignty in the Face of Treaty Obligations: An Analytical Study of Rockhopper v Italy

When Italy signed the Energy Charter Treaty (ECT), its main goal was to attract foreign capital to its energy sector by promising a stable legal system. However, as global warming became a major international concern, especially following the 2015 Paris Agreement, Italy began passing stricter environmental laws. Even so, it remained bound by the treaty while in the process of lawfully withdrawing from it.

Trusting Italy’s older laws and regulations, a company called Rockhopper invested heavily in the Ombrina Mare offshore oil project. The company followed the rules, obtained the necessary permits, and even passed an environmental compatibility check. Yet, right before they received the final green light to begin extraction, Italy abruptly banned oil operations near its coast. This new legislation completely shut down the project, leaving the company with a stranded investment and zero returns.

This situation created a major legal clash:

• Italy’s argument: The state retains the sovereign right to change its domestic laws to protect the environment and its citizens.
• Rockhopper’s argument: Italy breached the legal promises it made under an international treaty, which the company explicitly relied upon when committing its capital.

The first issue this paper highlights is whether states are legally permitted to invoke domestic sovereignty as a justification to avoid implementing previously agreed-upon treaty obligations, rather than utilizing the treaty’s designated withdrawal mechanisms.

By examining the facts of the dispute alongside domestic and international legal rules, this study explores how to balance sovereign regulatory power with the need for a secure, predictable environment for foreign economic investments.

1. Introduction and Background

The arbitration in Rockhopper v Italy under the Energy Charter Treaty (ECT) highlights the ongoing tension between international investment protection and domestic environmental regulation, The main situation in the dispute was whether Italy’s decision to ban offshore drilling within twelve miles of its coast breached its obligations under the ECT, specifically regarding the Fair and Equitable Treatment (FET) standard and unlawful expropriation. While the tribunal at the end worked in favor of the investor, the decision raises important question, are the sates allowed to invoke sovereignty as a way to avoid implementing the treaty’s obligations that they previously agreed upon when signing the treaty, instead of just getting out legally from the treaty?

2. Legitimate Expectations and the FET Standard

A primary issue in the case was the application of the FET standard, and specifically whether Italy frustrated Rockhopper’s legitimate expectations. It is generally accepted in investment arbitration that legitimate expectations arise when a host state makes specific representations to an investor or creates a stable legal framework that induces the investment. In this case, Rockhopper relied heavily on the Italian administrative framework. They had obtained an exploration permit, found hydrocarbons, and successfully applied for an environmental compatibility decree. Under Italian law at the time, specifically DPR 484/1994, getting this environmental decree meant the Ministry of Economic Development was basically required to issue the final production concession shortly after within 15 days of aquiring environmental decree.

Because Rockhopper had essentially completed the regulatory process, the tribunal found that Italy had created a legitimate expectation that the project would go ahead. When the Italian parliament subsequently passed the coastal drilling ban, the tribunal held this was a breach of FET.

However, this strict application of legitimate expectations is problematic from a regulatory perspective. It treats the host state’s administrative pathway like a stabilization clause. Even though Rockhopper had reached an advanced stage in the permitting process, environmental law is supposed to be dynamic. The government decided to ban drilling to protect its coastal environment in response to public concerns and broader climate goals. By ruling that a preliminary environmental assessment creates an absolute right to a production concession, the tribunal basically froze Italy’s regulatory framework in place. If tribunals continue to interpret administrative milestones as binding guarantees that the law will not change, it severely limits a state’s regulatory space. Investors in the fossil fuel sector should arguably foresee that environmental regulations are subject to change, rather than expecting absolute legal stability, but in this case the (ECT) had Article 10(1) of the Energy Charter Treaty provides for Fair and Equitable Treatment, which arbitral tribunals have interpreted as including the protection of an investor’s legitimate expectations, whcih brings to our attention a very important part that must be highlighted, italy already took a step forward towards FET standard and having the project reaching this advanced level and with all the investments taking place, a very legitimate expectation has already taken place and even if the administrative authority in italy has the discretionary power in making the final decision about the production concession, there is a legitimate expecxtation that has taken place in front of the investor, whether from the legal proceedings or the legal italian provision ( article 16(3) ) that sates “Il Ministero, entro quindici giorni dalla notifica da parte del Ministero dell’ambiente della pronuncia di compatibilità ambientale, emana il decreto di conferimento di concessione di coltivazione.”, which means After the Ministry of Environment communicates the positive environmental compatibility decision (VIA), the Ministry issues the production concession decree within 15 days, as “The Italian tribunal and the arbitral panel both read this provision not as a description of ordinary administrative practice but as a mandatory procedural obligation, meaning that once the environmental compatibility decree was issued, the Ministry had no legal basis to withhold the production concession. The fifteen-day timeframe was therefore not a guideline but a binding deadline, and Rockhopper’s expectation that the concession would follow was grounded in Italian law itself, not merely in commercial optimism.” which leads us again to say that there is a solid legitimate expectation.

3. Police Powers and Indirect Expropriation

Aside from FET, the tribunal also had to consider indirect expropriation and Italy’s defense based on the police powers doctrine. Under customary international law, a state does not have to pay compensation if a measure that negatively affects an investment is a bona fide, non-discriminatory regulation enacted for the public welfare. Italy argued that the twelve-mile ban was exactly this — a general environmental law protecting the marine ecosystem and the coastal economy, applying to everyone in that zone and not targeting Rockhopper specifically.

Despite this, the tribunal found that the ban constituted indirect expropriation. It focused almost entirely on the economic impact on the investor. Because the drilling ban completely deprived the Ombrina Mare project of its economic viability, the tribunal applied the sole effects doctrine, holding that the severity of the financial loss established expropriation regardless of the state’s intent.

At first glance, this reasoning appears inconsistent with how tribunals handle other public interest regulations. In Philip Morris v Uruguay, for example, tribunals were willing to examine the purpose of the regulation and defer to the state’s police powers even when the investor suffered substantial financial losses. However, the distinction in Rockhopper is critical: Uruguay’s plain packaging measures applied uniformly across an entire industry, whereas Italy’s ban fell on a geographically defined zone that extinguished one investor’s near-complete project almost precisely. More importantly, what happened to Rockhopper was not a reduction in investment value but a complete and total deprivation of economic viability. That distinction — between partial loss and total destruction of value — is what separates legitimate regulation from compensable expropriation under ECT Article 13.

This matters because Italy signed the ECT in 1994 at a time when climate regulation was not a significant legal or political force. The treaty’s investment protections, including Article 13’s prohibition on indirect expropriation, reflected that context. VCLT Article 26 requires every treaty in force to be performed in good faith, and VCLT Article 27 prevents a state from invoking its internal law to justify non-performance. These principles are not suggestions — they are the foundational rules of the international legal order that Italy voluntarily accepted. Italy retained the right to regulate its environment, but it accepted under ECT Article 13 that measures substantially depriving an investor of economic value would require compensation. The police powers doctrine describes one side of the analysis. ECT Article 13 describes the other. When the two conflict, the treaty obligation governs — and the lawful path to changing that obligation was always available through ECT Article 47.

4. Treaty Obligations and the Sunset Clause

The point to consider is how the case interacts with general treaty law. From a strict international law perspective, Italy’s sovereignty does not allow it to just ignore its treaty obligations. Under Article 27 of the VCLT, a state cannot use its internal laws to justify failing to perform a treaty. Italy signed the ECT voluntarily, which means they accepted the obligation to protect foreign investments.

Italy actually did try to use the proper legal mechanism to regain its regulatory autonomy by formally withdrawing from the ECT in 2016. The issue here was the ECT’s sunset clause in Article 47. Because Rockhopper made its investment before the withdrawal took effect, the sunset clause meant the investment remained protected for another twenty years. So, the tribunal was legally correct to hold Italy to the terms of the treaty because the sunset clause applied exactly as it was drafted. But practically, this shows a significant flaw in the system, A twenty-year survival clause means that states are locked into protecting legacy fossil fuel investments long after they have decided to change their environmental policies, It traps states in a cycle of liability even after they try to lawfully exit the treaty, but at the end it does not change the fact that there is a treaty signed and there is a legal path for the withdrawal.

5. Conclusion

At the end, the tribunal’s decision in Rockhopper v Italy is legally logical if you apply traditional investment law principles strictly. The state created a detailed administrative process, the investor followed it, and the state changed the rules at the very last minute, completely destroying the investment. However, the reasoning the tribunal used to get to that award highlights major issues in the ISDS system. By expanding legitimate expectations to cover uncompleted administrative processes and refusing to apply the police powers doctrine to environmental regulations, the tribunal prioritized investment protection over the state’s right to regulate. The rigid application of these rules, along with the ECT’s sunset clause, makes it increasingly difficult for states to adapt their laws to deal with environmental concerns, but this at the same time logical because the treaty was made at a time the climate change did not have much focus as today and was mainly focusing on the investment protection to attract investments at that time. This case highlights as well that there is a way to handle that situation which is by first getting lawfully out of the treaty and building new ones with much focus and consideration to the enviromental law and the climate change as with the paris convention in 2015 was somehow the first step towards taking measures in regards to the climate change, as well as Sovereignty in international law is not absolute once a state voluntarily enters a treaty regime, as where the state starts to agree to certain articles and matters on how it exercises that power.