Article by Prime Minister Kyriakos Mitsotakis published in The Times, Frankfurter Allgemeine Zeitung, and Le Monde

In seeking to predict the future political scientists often look to the past, to shared history. The relationship between my country Greece and its neighbour Turkey is no exception. History teaches us that there are reasons for optimism, and areas of deep concern. Today the question of what that future holds – conflict or co-operation – has never mattered more.

When I became prime minister in July last year I was cautiously optimistic. Nothing prevented me from believing that Greece and Turkey could not be friends. After all, many of my predecessors had managed to overcome seemingly insurmountable obstacles. Leaders like Eleftherios Venizelos, my great-uncle, who signed a peace and friendship agreement with Kemal Attaturk back in 1930. Of course there have been tensions since, but the good days have outweighed the bad.

When we met last Autumn, I told President Erdogan that we were destined by geography to be neighbours, and as such we needed to co-exist, to live peacefully side by side. I made a point of extending the hand of friendship and cooperation. I talked of open dialogue, of a desire for progress, and of my willingness to act as a bridge builder for Turkey in Europe.

Sadly, things have not worked out quite like that. Since that first meeting Turkey has appeared less like a partner and more like a provocateur. Late last year President Erdogan signed an illegal maritime agreement with one side fighting Libya’s bloody civil war. Since Turkey and Libya do not have opposite or adjacent coasts, the agreement was declared by most of the international community and legal experts as null and void and a violation of the sovereign rights of third countries, including Greece.

In March Turkey made concerted moves to encourage and facilitate desperate attempts by migrants to cross into Greece. We defended our border with the support of our EU partners. Our collective message was clear – Greece’s borders are the EU’s borders and we will protect them.

And this summer, in response to the signing of a long standing, legal and internationally recognised maritime agreement between Greece and Egypt, President Erdogan sent his navy to support an attempt to explore for gas deposits in an area of the Eastern Mediterranean that both Greece and Turkey claim rights to, and is still undelimitated. Under the UN Convention on the Law of the Sea this was a unilateral act in breach of international law.

Greece will never and has never sought to escalate these tensions, regardless of the provocation. But what began as ugly political posturing has turned decidedly threatening in recent weeks. Each passing day, the Turkish government presents another spurious claim or disseminates another untruth. Bellicose language, nationalist propaganda, aggressive militarism, the purchase of weapon systems from Russia that pose a threat to NATO, the conversion of world heritage monuments into mosques, illegal maritime activity, and threats of war.

Turkey’s rhetoric is from a bygone age. It talks about enemies, martyrs, struggle, and a willingness to pay any price. This is the language and behaviour of a candidate country threatening not just two members of the European Union, Greece and Cyprus, but the EU itself; something that’s of grave concern to member States.

In this new geopolitical landscape Turkey appears increasingly isolated. As Greece has forged strong partnerships with countries such as Israel, Egypt, and the UAE, Turkey has acted alone, posturing in the Eastern Mediterranean, interfering in Syria and Libya, and openly supporting Hamas. France, which has vital national interests in the Mediterranean has stood by us and has bolstered its military presence in the area. The US State Department has clearly condemned what it considers to be Turkish unilateral aggression.

Throughout all this I have kept an open mind about dialogue. When Berlin offered to broker talks, we sat down in good faith to try to find common ground. We even managed to get to a written understanding. Only for Turkey to walk away, disclosing as it went what were informal but private discussions.

The hopes that still bind me to Turkey do not blind me to the reality. We do need dialogue, but not when held at gunpoint. What threatens my country’s security and stability threatens the well-being and safety of all EU member states. It risks undermining the NATO alliance. And it threatens the rule of law internationally. Greece has the military capacity to fend off any Turkish aggression. But surely a military incident between our two countries is in nobody’s interest.

Later this month EU leaders will meet in special session to decide how to respond. If Turkey refuses to see sense by then, I see no option but for my fellow European leaders to impose meaningful sanctions. Because this is no longer just about European solidarity. It is about recognising that vital interests – strategic European interests – are now at stake. If Europe wants to exercise true geopolitical power, it simply cannot afford to appease a belligerent Turkey.

There is still time for Turkey to avoid sanctions, to take a step back, and to chart a path out of this crisis. Turkey simply needs to refrain from its naval and scientific activity in non delimited waters, and reign in its aggressive rhetoric. They should stand down, return to the table, and pick up from where they left off when they quit exploratory talks in 2016. And if we cannot agree then we must seek resolution at the Hague.

The choice is stark. Turkey can engage, and find common ground, or it can continue to behave as the aggressor, posturing on the fringes of Europe, and pay a significant economic price for doing so. It can choose between Greece being a bridge or being a barrier to partnership and progress.

If Turkey were to choose the bridge, I believe that it would still be possible for President Erdogan to strike an ambitious far reaching agreement with the EU that benefits us all. Disputes are settled not through force, subterfuge, or manipulation, but peacefully and through mutual respect and understanding. It doesn’t have to be like this. Resolving this is simple. We sit down. We discuss our differences. And we try and reach an agreement. If we can’t then we let the International Court decide. What after all has Ankara to fear from the rule of law?

Kyriakos Mitsotakis is the Prime Minister of Greece