The trilateral partnership took shape some 15 years ago after Israel’s ties with Turkey deteriorated, even if it was initially framed in the language of energy cooperation and regional diplomacy.

Prime Minister Benjamin Netanyahu will host his Greek and Cypriot counterparts in Jerusalem on Monday as part of a trilateral partnership that has steadily changed character.

The partnership took shape some 15 years ago after Israel’s ties with Turkey deteriorated, even if it was initially framed in the language of energy cooperation and regional diplomacy.

But what was once implicit has now become more explicit, with concerns about Turkey’s intentions increasingly defining the trilateral agenda.

A decade ago, natural gas provided both the language and the legitimacy for building closer ties with Greece and Cyprus, two countries that for decades were among the most critical of Israel in Europe. Gas pipelines, export routes, and the connection of electrical grids were ways to deepen cooperation among the three countries without explicitly framing it as an alliance against Turkey.

But today, as energy projects fade or change form and regional tensions have sharpened, that caution has given way to more candor. Security cooperation – once a talking point that appeared well after gas was discussed – has become the central pillar of the relationship.

On the eve of this summit, reports emerged – and later denied – that the three countries were considering putting together a rapid-response force composed of military units from each country.

The roots of this partnership lie in the early years of this century, when Israel’s offshore gas discoveries coincided with a sharp deterioration in its ties with Ankara, brought about by the election of Recep Tayyip Erdogan as prime minister in 2002.

Historic Turkey rivals become new Israeli partners

As Erdogan dramatically altered Turkey’s relationship with Israel, seen most vividly in the Mava Marama incident in 2010, Israel lost an important strategic ally. As a result, it sought new partners in the region to take Turkey’s place, and Greece and Cyprus – both historic rivals of Turkey and wary of its regional aims – emerged as natural alternatives.

Energy cooperation provided the initial framework – something that could serve as a foundation for closer ties, bring Israel nearer to Europe, and deepen coordination with two EU member states without immediately defining the alliance as a counterbalance to Turkey.

At the time, the gas story was compelling, with an ambitious idea of a pipeline running from Israel through Cyprus to Greece and onward into Europe. The EastMed pipeline, as the project was known, was expensive and technically challenging, but it offered a vision around which this new alignment could coalesce.

This alignment was all the more striking because it broke with history. Greece and Cyprus had been among Israel’s harshest and most consistent critics in Europe for decades. The sight of Israeli, Greek, and Cypriot leaders standing together at summits in Nicosia and Athens represented a significant diplomatic shift. Gas did not erase political differences, but it created common interests strong enough to override them.

Turkey, however, always lurked in the background. The proposed energy routes were attractive not only because they connected Israel to Europe, but also because they went around Turkey. Still, this was rarely stated outright. The emphasis remained positive: cooperation, development, and regional stability. Energy allowed all three countries to advance the alliance as a counterweight to Turkey without presenting it as such.

This framing was deliberate. Israel was still testing whether its relationship with Ankara could get back on track. Greece and Cyprus, for their part, preferred not to frame their diplomacy explicitly as anti-Turkish. Gas provided a neutral vocabulary – one that enabled progress without forcing a confrontation.

Over time, however, the limitations of that approach became clear. The EastMed pipeline to Europe never got off the ground, despite endless discussion. The project quietly slipped off the agenda due to its immense costs, engineering challenges, shifting energy markets, and, eventually, the withdrawal of US support in 2022.

Energy cooperation did not disappear altogether, however. Gas exports to Egypt – and from there to Europe – moved forward. Discussions about undersea electricity cables linking Israel directly to Cyprus and then to Greece and the European electricity grid began to advance. But gas no longer carried the political or strategic weight it once did. It could not sustain the relationship on its own.

Instead, the relationship was sustained by enhanced security cooperation, something that had been developing all along.

Even before the ambitious gas projects fell by the wayside, Israel and Greece were building an impressive web of military ties. Israeli pilots trained in Greek airspace after access to Turkish skies was closed. Joint exercises expanded in scope and frequency. Intelligence cooperation deepened.

Cyprus also steadily strengthened its security dialogue and cooperation with Jerusalem and even let IDF soldiers train there.

By the early 2020s, this cooperation had matured into an institutional arrangement. Long-term defense agreements were signed. Major procurement deals moved forward. Coordination among air, naval, and ground forces became routine rather than exceptional. The relationship deepened.

What has changed in recent years is not the existence of that cooperation, but the context in which it is now being discussed.

Turkey’s actions have sharpened threat perceptions across the region. Airspace violations over the Aegean, maritime maneuvers in the Mediterranean, diplomatic and military activism in Libya, and efforts to entrench influence in Syria have made clear to Athens, Nicosia, and Jerusalem that Turkey is flexing its muscles and testing limits.

For Greece, the concern is less about full-scale war than about escalation through miscalculation. For Cyprus, it is the permanence of a divided island backed by an overwhelming Turkish military presence. For Israel, it is possible that Turkish deployments or influence could one day complicate operational freedom over the skies of Lebanon and Syria.

These are not identical concerns. But they overlap.

That overlap explains why ideas that once would have been politically sensitive are now being openly aired – and denied. Reports in recent weeks about deliberations over a trilateral rapid-response framework involving Israeli, Greek, and Cypriot forces have drawn swift official pushback, stressing that no standing joint force is being established. Those denials matter. They reflect real constraints and a clear desire to avoid formal alliance commitments.

But they also reflect something else: a willingness to let it be known that the three countries are thinking together about crisis response and how they could operate together in a crisis. A decade ago, such discussions would have remained entirely behind closed doors. Today, even the act of denying them sends a message.

There is an irony here. Gas was long portrayed as the foundation of the Israel-Greece-Cyprus partnership. But Turkey was the reason the partnership was formed in the first place, even if that was not how it was packaged at the time.

As the ambitious energy projects faded or changed form, what remained was the core of the relationship: security cooperation, defense procurement, intelligence sharing, and close diplomatic coordination. That core has proven more durable than any infrastructure plan.

Turkey, once the background constant, has become the catalyst that clarifies why all this matters; the central factor – in today’s fluid regional order – driving the Israel-Greece-Cyprus alignment in the first place.