Greece has ordered 18 French Rafale fighter jets to upgrade its military. The aircraft will be deployed from next summer. The deal takes place as tensions remain high between Greece and Turkey over a territorial dispute in the Mediterranean. French Minister of Defence Florence Parly is to travel to Athens Monday to ink the deal after it was formally approved by Greek parliament last week.The contracts value an estimated 2.5 billion euros for six new aircraft and 12 used – the latter sold for some 400 million Euros.France will throw in armament: Scalp cruise missiles, long range Meteor air-to-air missiles, medium range MICA air-to-air missiles and AM39 Exocet anti ship air-sea/surface missiles.The deal also involves pilot training and maintenance. The Greek air force is no stranger to French fighter jets. According to a 2020 press release of the Dassault group, in 1974 Athens ordered 40 Mirage F1 from Dassault Aviation, 40 Mirage 2000s in 1985 and 15 Mirage 2000-5s in 2000.Dassault also sells its aircraft to Egypt, India and Qatar.Defense World reported in December that the 18 Rafales would operate from Squadron 332 in Tanagra, the main air base of the Hellenic Air Force, north of Athens.Neighbourly tensionsTensions between Greece and Turkey reached boiling point last year. The two Nato members were locked for weeks in a tense standoff in the Eastern Mediterranean, where Turkey is prospecting the seabed for energy reserves in an area Greece claims as its continental shelf. In August, France deployed two of its own Rafale fighters and navy ships to join Greek naval patrols as Athens and Ankara flexed their military muscle.In September, dogfights between Greek and Turkish fighter pilots multiplied over the Aegean Sea and the Eastern Mediterranean. A Turkish and a Greek frigate collided, reportedly causing minor damage to the Turkish frigate but no injuries.The crisis was the most serious in decades. The neighbours have come to the brink of war three times since the mid-1970s, including once over maritime resources in the Aegean Sea.Casus BelliThe English speaking Ekathimerini newspaper reported that Turkish Foreign Minister Mevlut Cavusoglu on Friday told Greece that in the event it extends its territorial waters in the Aegean it will be casus belli, or cause for war. The remarks follow Greek plans to extend its territorial waters in the eastern part of the Crete Island in the Mediterranean.“Turkey has vital rights and interests in the semi-enclosed Aegean Sea, where special geographical circumstances prevail,’’ according to Cavusoglu.The threat of war comes days before Turkey and Greece are due on Monday to resume, after a 5-year hiatus, exploratory talks they have been conducting since the 1990s – coinciding with the visit of the French minister of defence.It will be the 61st round of the Greek-Turkish talks. According to the Turkish Hurriyet Daily News, they are expected to focus on bilateral disputes, including maritime boundaries and drilling rights in the region.