(CNN)Tension is simmering in the waters of the Eastern Mediterranean as Greece and Turkey, NATO allies but historic rivals, inch toward a possible military confrontation that could end up engulfing the region.
NATO allies are facing off in the Eastern Mediterranean. The conflict could entangle the entire region
Naval vessels from both countries made a show of force in the contested region of the Eastern Mediterranean this week as a race for gas and oil reserves adds a new point of friction to old disputes.
Hostilities first flared when Ankara announced that it is extending the duration of a seismic exploration mission in the disputed waters originally expected to end on Monday in a maritime navigational note using the global NAVTEX system. The Oruc Reis survey vessel is accompanied by naval ships and the Turkish defense ministry announced maritime exercises in the area on Tuesday.
Greece considers the Turkish gas exploration illegal. Athens responded to Ankara by issuing a counter NAVTEX message and announcing naval exercises in the same location to the south of Turkey and the Greek island of Kastellorizo, which lies just over one mile from the Turkish coast.
On Wednesday, Turkey confirmed that its navy warships were conducting "maritime trainings" with a US vessel in the Eastern Mediterranean.
They're not the only ones: France and Italy are joining Greece and Cyprus for joint naval exercises, French and Italian officials said, a move likely to raise the temperature further in the region.
"The Eastern Mediterranean has transformed into a space of tensions," French Defense Minister Florence Parly tweeted Wednesday. "The respect of international law should be the rule and not the exception. With our Cypriot, Greek and Italian partners we will start military exercises from today with maritime and air methods."
The Italian navy said in a statement calling for "stronger cooperation and dialogue" that it would be taking part in an exercise off Cyprus, with the naval units of France, Cyprus and Greece, between August 26-28. The Italian ship involved in that also took part in a four-hour exercise with the Turkish navy on Wednesday.
While Greece and Turkey have been engaging in gunboat diplomacy that has pulled more countries into the dispute, Germany has been looking to de-escalate the tensions that threaten to spill over regionally.
"The conversation windows between Greece and Turkey must now be opened further -- and not closed. In addition, instead of new provocations, we now finally need steps to relax and an initiation of direct discussions," German Foreign Minister Heiko Maas tweeted ahead of visits to both Athens and Ankara on Tuesday in an effort to get the two countries back to the negotiation table.
Following a meeting with Maas on Tuesday, Greek Foreign Minister Nikos Dendias said in a joint press conference: "Turkey continues to act unlawfully, to escalate and to provoke, despite the urgings of its neighbors, partners and allies.
"Greece will defend its sovereignty and sovereign rights in the name of the law. Greece will defend its national borders and European borders, the sovereignty and sovereign rights of Europe ... But Greece has proven that it is and always will be ready for dialogue. However, there can be no dialogue under threats."
Ankara has also said it is open to dialogue, but that must be without preconditions and center around a just distribution of resources.
"We are ready to negotiate ... but no one should try to impose preconditions on Turkey, particularly not ones determined by Greece," Turkish Foreign Minister Mevlut Cavusoglu said in his joint press conference with Maas.
Greece needs to drop its "maximalist ideas" and "let common sense prevail," Cavusoglu said. "If we had a just distribution instead of one-sided impositions, we would all benefit," he said.
German efforts to bring about an agreement between Greece and Turkey failed earlier in July. Turkey paused seismic surveys for gas in the disputed area while negotiations were ongoing. But, according to the Turkish government, those talks failed after Greece signed a partial maritime demarcation agreement with Egypt.
Since then Turkey has been carrying out surveys in the contested waters. "Our drill ships continue their operations as planned. Our case is strong under international law. Greece gangs up with certain countries to seem right, because it lacks credibility," Turkey's Energy Minister Fatih Donmez said on Tuesday.
Donmez appeared to be referring to the support Greece, which is a member of the European Union, has received from France and the United Arab Emirates.
The territorial dispute between Turkey, Greece and the divided island of Cyprus has been rumbling regionally for years. But, "the region's offshore natural gas resources have changed everything [in the eastern Mediterranean] over the course of the past five years," says Michael Tanchum, a senior fellow at the Austrian Institute for European and Security Studies. This has turned it into "a key battleground in which larger geopolitical fault lines involving the EU and the Middle East and North Africa region converge," he added.
The disputed area is also linked to territorial claims from Cyprus. The island remains divided between the Greek-speaking EU member and internationally recognized Republic of Cyprus in the south, and the self-proclaimed Turkish Republic of Northern Cyprus, which is recognized only by Turkey.
The Republic of Cyprus has granted international companies, such as Italy's ENI and France's Total, licenses to exploit gas reserves in the Eastern Mediterranean. The Turkish government has argued that this cuts out Turkish Cypriots from hydrocarbon resources in the region.
According to a 2010 study by the US Geological Survey, there is an estimated 1.7 billion barrels of recoverable oil and 122 trillion cubic feet of gas in the Levant Basin section of the Eastern Mediterranean.
"Both France and its close partner the United Arab Emirates compete with Turkey f