Agence France-Presse reported in June 2014 that Chinese shipyards had received orders to construct 190 vessels for Greek owners.

"The links played a crucial role in mobilizing the Greek state to 'discover' China, which was developing exports and building on a mutually beneficial scenario of Greece being a door to Europe," says Petropoulos, who wrote a paper on the foreign policy shift with his colleague, Asteris Huliaras, in 2013.

Greece aimed to conquer markets in Balkan countries before its debt problems caused an undignified retreat, primarily of its banks, from the region. But Tsinghua University's Trigkas says an often overlooked aspect of the Piraeus Port deal and accompanying infrastructure investments is the impact on regional integration.

The Hungary-Serbia Railway to connect Budapest with Belgrade is due to be completed in 2017. The bullet train, together with Piraeus, will be the European part of the China-Europe land-sea express route, consolidating Greece as a transportation hub, linking the 21st Century Maritime Silk Road with the Silk Road Economic Belt on land.

Economic integration between Central and Eastern Europe will unleash enormous economies of scale for European industry, Trigkas says. The recovery of the Mediterranean region and the economic integration between Africa and Southern Europe will provide enormous positive externalities for Northern Europe as well. In the overarching Silk Road project for the Mediterranean, Greece could play a catalytic role, Trigkas says.

"For the first time in history, the Balkans are being integrated economically to a great extent," he says. "China persisted with the port agreement even though demagogy from the Greek political class had been out of proportion. It is important for Greece at this moment to seize the opportunity."

For Greece, forced into humiliating negotiations with EU and global financial institutions for bailouts to resolve its debt crisis, the Cosco deal and its attendant Chinese interest have come as a shot in the arm.

The Piraeus deal is being seen as a catalyst in the so far lackluster sale of Greek state assets, as demanded by its creditors, the European Union and the International Monetary Fund, in return for bailouts.