Athens-Rome maritime deal a message to Ankara

The signing on Tuesday of a maritime border demarcation agreement between the Greek and Italian foreign ministers, Nikos Dendias and Luigi Di Maio, was seen as a clear message to Ankara regarding Greece's diplomatic clout and its determination to move ahead with its plans on the basis of international law. 

The agreement, which is an extension of a 1977 accord, paves the way for Greece and Italy to explore for and exploit marine resources. The agreement must be ratified by both national parliaments.

It came amid mounting tension between Greece, Cyprus and Turkey, and after Ankara signed a contentious accord with the Tripoli-based government in Libya, which it claims gives it rights in parts of the Eastern Mediterranean that overlap Greece's continental shelf.

"The delimitation of maritime zones is accomplished with valid agreements, not with invalid ones like...