New tensions between the two longtime rivals flared up in mid-August, when Turkey deployed the research vessel Oruç Reis, flanked by two warships, to explore for oil and gas in contested waters between the islands of Crete and Cyprus. Greece accused Turkey of violating its sovereign rights — and dispatched warships of its own, precipitating a collision between a Greek frigate and a Turkish warship.
How Greece and Turkey interpret international maritime law is key to understanding what’s going on in this contested part of the Mediterranean, a conflict that risks drawing in other countries, including Germany, France and the United Arab Emirates. Here’s what our research tells us.
Parties are doubling down on dueling interpretations of the law of the sea
The U.N. Convention on the Law of the Sea (UNCLOS) asserts that countries may claim a territorial sea extending up to 12 nautical miles (nm) from their coasts, including sovereignty over the offshore oil under those waters. UNCLOS also grants nations the right to claim “sovereign rights and jurisdiction” over the waters, seabed and subsoil of an exclusive economic zone (EEZ) extending up to 200 nm, as well as a continental shelf extending up to 350 nm in certain circumstances.
This might sound straightforward, but in semi-enclosed seas like the Aegean and Mediterranean, geographical limitations and overlapping claims make it near-impossible for any country to stake out its full jurisdiction. For this reason, Greece and Turkey customarily have limited their claims within the cramped Aegean Sea to six nm. Although Greece retains the right to extend its claim to 12 nm, Turkey has long warned that such a move would be tantamount to an act of war.
An even greater source of contention between Athens and Ankara is their conflicting claims to EEZs and continental shelves. UNCLOS does not spell out how countries should address overlapping claims to such zones, instead asking countries to adopt “equitable” compromise solutions. Equitability is often in the eye of the beholder though, especially in the context of fraught historical circumstances, such as the dispute over Cyprus and a handful of other smaller islands between Greece and Turkey.
Further complicating matters, Turkey has never ratified UNCLOS — and specifically rejects the convention’s provision that islands are entitled to continental shelves of their own. Since most of the islands in the Aegean are Greek territory, Turkey uses this legal position to claim rights to offshore oil in waters outside the territorial seas of Greek islands, arguing that this area is part of Turkey’s continental shelf.
Greece, a party to UNCLOS, rejects the Turkish position, arguing that the principles in UNCLOS — including the entitlement of islands to continental shelves — have come to represent customary international law and thus also apply to Turkey. Reflecting this stance, Greece argues that Turkey’s recent exploration is on a continental shelf extending from the Greek islands of Crete, Karpathos and Rhodes and thus violates Greece’s sovereign rights.
Maritime tensions are a microcosm of other politics
Turkey’s behavior may also reflect Erdogan’s desire to boost his flagging popularity, reflected by his Justice and Development Party’s losses in local elections in March 2019. During the past 17 years, Erdogan oversaw significant economic growth driven by current account deficits, which facilitated his hold on power as either prime minister or president. But an economic slowdown in 2018 and then the broader pandemic and global downturn saw the already weak Turkish lira tumble to a historic low in August.
Erdogan has consistently used foreign policy to signal Turkey’s strength and pitches his efforts to strengthen Turkey’s maritime jurisdiction as protecting the country’s “Blue Homeland.” Before Erdogan’s tenure, Turkish foreign policy tended to prioritize outreach toward Europe, a legacy of Turkey’s founder Mustafa Kemal Atatürk. Erdogan’s approach is often characterized as “neo-Ottomanism,” emphasizing Turkey’s robust imperial Ottoman heritage to justify closer ties with, and sometimes intervention in, Muslim societies previously under Ottoman control.
But other regional players see Erdogan’s assertive maritime moves as a potential threat to their own ambitions. In 2019, Turkey signed a maritime agreement with the Libyan Government of National Accord (GNA) that ignored Greece’s claim to continental shelves from islands such as Crete. In turn, Turkey offered material support to the GNA, placing it in direct conflict with the United Arab Emirates, which supports rebel forces in Libya.
Erdogan’s maritime deal with the GNA also provoked resistance from E.U. members and prompted Greece and Egypt to sign their own maritime deal. The maritime dispute between Greece and Turkey has thus become a microcosm of complex regional political dynamics.
International law might not ease the conflict
Ideally, international laws help prevent maritime disputes from escalating to war by clarifying the limits of countries’ jurisdiction over the ocean and providing a process for arbitration of overlapping claims.
In principle, Greece and Turkey could resolve their dispute short of war by dividing up maritime space or jointly developing oil resources. However, as they double down on legal claims that support their exclusive jurisdiction and control over coastal resources, both governments nurture domestic political grievances and international antipathies that may make it harder to back down and accept compromise.
Due to these dynamics, international law offers no panacea for resolving the current quarrel. International arbitration could be a useful mechanism for settling the dispute — but only if both parties trust the process will result in an equitable and acceptable outcome. In the meantime, it is unlikely the two countries will be able to move beyond the current impasse unless they exercise restraint in oil exploration and military deployments, and accept that compromise is preferable to conflict.
Rachel Esplin Odell is a research fellow in the East Asia program at the Quincy Institute for Responsible Statecraft. She wrote her PhD dissertation about countries’ disagreements over how to interpret the law of the sea. Follow her on Twitter @resplinodell.