For more than a decade, Turkey has made increasingly spurious and expansionist maritime claims that undermine international law, exclusive economic zones, and the security of Greek islands. While Athens objected and dismissed the legality of Ankara’s moves, it remained largely quiet. That now has ended.
Greece has moved to formally stake its maritime claims in the Eastern Mediterranean, combining new legal filings with action at sea in a contest that will test regional power balances. Athens’ first Maritime Spatial Plan, submitted to the European Commission, sets the maximum potential limits of its continental shelf, records agreements on maritime zones with Egypt and Italy, and establishes two national marine parks, one in the Ionian Sea and the other in the Aegean, covering the Southern Cyclades and extending to the islets of Kinaros and Levitha, which Turkey disputes. These steps give Greece a formal record of its positions in European institutions and an operational presence in waters Ankara considers sensitive.
For decades, Athens avoided publishing official maps or taking steps that might trigger escalation, preferring to rely on quiet diplomacy.
The decision to make these claims explicit reflects a shift in Greek strategy. For decades, Athens avoided publishing official maps or taking steps that might trigger escalation, preferring to rely on quiet diplomacy. That restraint left its positions less visible to international bodies and open to competing interpretations. By submitting a comprehensive plan, Athens now sets down legal markers that can be cited in future negotiations or disputes, while signaling to its neighbors and its partners that it intends to translate its claims into sustained action.
Turkey has countered by reinforcing its own claims and challenging Greece’s legal framing. Within days, Ankara unveiled a maritime plan that bisects the Aegean and revived the “grey zones” theory, asserting that sovereignty over an unspecified number of islands is unsettled by treaty. Turkey moved through diplomatic channels in Libya to contest Greece’s median line south of Crete, an area Turkey claims under its 2019 maritime memorandum with Tripoli. The Turkish approach seeks to undercut Athens’ claims by keeping disputes open, creating room for tactical moves at sea, and projecting that maritime boundaries remain fluid. These actions are consistent with Turkey’s “Blue Homeland” doctrine, which aims to expand Ankara’s maritime reach and deter its encirclement in the Eastern Mediterranean.
One of the most contested areas—and a potential flashpoint—lies south of Crete. Chevron has expressed interest in two offshore blocks, with license decisions expected in September. Senior Greek officials argue that exploration would challenge the Turkey-Libya deal and solidify Greek rights by placing a commercial presence in the disputed zone. Ankara faces a calculation: Obstructing such operations risks friction with the United States, while allowing them to proceed could enable Greece to turn legal claims into sustained facts at sea.
In recent years, rare ventures into contested or sensitive waters have not always ended in Athens’ favor.
Whether Greece can hold its ground in such operations will depend on political will, a question raised by recent precedent. In recent years, rare ventures into contested or sensitive waters have not always ended in Athens’ favor. In mid-2024, tension flared near Kassos but left Ankara’s limits in place. If future operations meet similar pushback, the cost of withdrawal—in credibility and strategic ground—could be high. The question is whether Athens will carry initiatives through when confronted with resistance. Such choices also will shape how outside powers, including the United States, calculate their role in contested waters.
Washington is already weighing that calculation. In Senate testimony, incoming Ambassador Kimberly Guilfoyle called Greece “a pillar of stability” and noted its high defense spending, major purchases of U.S. military systems, and expanding role in regional energy supply. She pledged to deepen cooperation in defense and energy, including liquified natural gas exports and new pipeline interconnections. Committee Chairman James Risch reaffirmed his opposition to Turkey’s return to the F-35 program and described Greek requests for U.S. support as justified. Beyond the defense sector, the United States also sees in Greece an anchor for energy diversification in Europe and a reliable partner in managing regional crises from the Black Sea to the Middle East.
For Washington, exploration south of Crete would place American assets in contested waters alongside one of its most dependable and capable allies. Backing that ally on the water would secure energy flows, protect shipping lanes, and anchor the alliance’s southeastern flank at a moment of heightened competition. The involvement of Chevron underscores that this is not only a diplomatic or military issue but also a matter of commercial and industrial weight for the United States. Choosing to reinforce Greek efforts would not only advance U.S. interests, but also send an unambiguous signal that in the Eastern Mediterranean, the United States and its partners, not America’s rivals, will set operational terms.
