Turkey has not signed the UNCLOS convention nor the treaty of Paris that gave Kastellorizo to Greece, wants to renegotiate the treaty of Lausanne, & has consistently refused since 1974 to refer the issues to the International Court of Justice https://www.globalsecurity.org/military/world/war/eez-east-med.htm

This creates a dangerous situation because there is no agreed legal framework between Greece and Turkey to resolve the dispute.

This is no excuse for Turkey to try to create facts on the ground (actually in the water)by taking advantage of its military superiority over Greece. , not only France, would be well advised to signal, including with military deployments, that this is totally unacceptable.

Germany, as a responsible power that believes in the rule of law, should see the seriousness of the situation: Germany is right to call for diplomacy, but military bullying must be off the table for a negotiation to succeed. That is the aim of the French deployment.