Turkey’s government is conducting so-called “lawfare” in the Mediterranean and Balkans, rendering the country a destabilising force in the region, said Andrew Carpenter, former foreign policy adviser to U.S. Vice President Joe Biden.

Turkey is flouting international norms by exploring for hydrocarbons off Cyprus, signing a maritime deal with Libya that includes Greek islands, and extraditing opposition figures from the Balkans via extrajudicial means, said Carpenter, senior director of the Penn Biden Center for Diplomacy and Global Engagement.

“In various different areas Turkey is being more a cause of the problem than a source of solutions, and that is why I think the relationship between the U.S. and Turkey is so fraught right now,” Carpenter told Greek newspaper Kathimerini.

Turkey is disrupting the rule of law by denying Cyprus the right to explore for hydrocarbons and by sending its own drill ships close to the island, Carpenter said. The tactic is creating animosity between Greek and Turkish Cypriots on the ethnically divided island and hinders forward movement on a political settlement to reunite the communities, he said.

The maritime agreement with Libya is another example of Turkey’s “lawfare” and a source of regional tension, Carpenter said.

Turkish plans to explore for hydrocarbons off the Greek island of Crete, citing a map drawn up with Libya as part of the maritime deal, is also increasing regional instability. While Greek-Turkish tensions over territory are long-standing, these latest moves should not be underestimated, Carpenter said.

“I think what it takes is the U.S. stepping in and having some very frank conversations, especially with the Turks,” he said. “Because, frankly, as I see the situation, it’s Turkey that is being more and more detached from the international normative system that has held for the last several decades.”