How EU threatned Greece with Turkey

"During a pivotal meeting with Merkel, French President François Hollande and European Council President Donald Tusk, Tsipras at one point received a thinly veiled threat that if he walked away and left the euro, Greece risked going it alone geopolitically, too. According to two officials in Brussels with knowledge of the exchange, the specter was raised of aggression from Turkey — a neighboring nation viewed in Greece as a historic antagonist."