Southeast of the “Iron Curtain” famously described by Winston Churchill in 1946, a new group of China-friendly nations is forming a north-south line that runs through the heart of Eurasia.

While this “Silk Curtain” — which runs from Hungary in the north to Greece in the south — does not represent an ideological divide, it does offer China strategic and economic access to a region near Western Europe, Africa and the Middle East.

Most notable are the growing ties between China and Serbia, the largest economy in the Western Balkans. Early last month, Serbian President Aleksandar Vucic was the first foreign leader to confirm he would attend China’s military parade on Sept. 3 to mark the 80th anniversary of the end of World War II.

Also last month, China and Serbia conducted joint special forces training in Hebei province, their first-ever military exercise together. Jie Gao, an analyst who studies the People’s Liberation Army and co-author of the newsletter PLA Watch, said China has been selling FK-3 air defense systems and CH-series drones to Belgrade, making Serbia  “the first European country to integrate these platforms.”

Economic ties are also growing. China-Serbia trade rose 22.8% in 2024 to $7.5 billion, according to the Statistical Office of Serbia. China is now Serbia’s third-largest trading partner, following Germany and Bosnia and Herzegovina. In 2020, China ranked 19th.

“China has replaced Russia as Serbia’s primary partner outside the Western world,” Vuk Vuksanovic, a senior researcher at the Belgrade Centre for Security Policy told Nikkei Asia. “The Serbian leadership understands that China is a rising superpower with a capacity that Russia — despite its resources, despite its great power status — simply does not have.”

For China, Serbia is a piece of a wider puzzle, according to Vuksanovic. “If you connect the dots, just take where the Chinese investments in Southeastern Europe are, and you see that four countries are important,” he said, pointing to Greece, North Macedonia, Serbia and Hungary. “These four countries are part of a single whole.”

Damjan Krnjevic Miskovic, who was part of the Serbian foreign ministry team that negotiated a strategic partnership with China in 2009, said, “the logic for us was very simple. China was a country that had never done us wrong.”

China, whose embassy in Belgrade was bombed by NATO forces in 1999, did not recognize Kosovo as an independent state. This was an integral part of the motivation for Serbia to engage with China “in a much more active way,” Miskovic recalled.

Hungary, Serbia, North Macedonia and Greece each have their reasons for accepting Chinese investment, Miskovic said. For Serbia, it was important to have another permanent member of the United Nations Security Council, in addition to Russia, on its side to block further negative developments on Kosovo.

In Greece, Chinese state shipping company Cosco owns the Port of Piraeus, the chief sea port of Athens. After renting a dock at the port in 2009, Cosco took a majority stake in 2016.

The Chinese investment in Piraeus began during the Greek government-debt crisis of 2009, “when the European Union was forcing the Greeks to adopt incredibly harsh economic measures,” Miskovic said. “You could say that China is taking advantage of unfortunate economic circumstances, but name me a great power that doesn’t.”

During a state visit early last month, Chinese Premier Li Qiang told his Greek counterparts that China was ready to cooperate on clean energy and artificial intelligence, China’s state-run Xinhua news agency reported.

Hungary is an EU and NATO member, but due to the controversial policies and statements of Prime Minister Victor Orban, including his friendlier stance toward Russia, the country is often at odds with other allies. North Macedonia has “even cheaper labor than Serbia, but it’s very difficult for the country to attract foreign direct investment. So the Chinese come in,” Miskovic said.

Donatienne Ruy, a fellow at the Washington think tank Center for Strategic and International Studies, said that while the Trump administration is currently occupied with other priorities, there was a diplomatic effort during the first Trump administration, in particular by then-presidential envoy for Serbia-Kosovo negotiations Richard Grenell, to seek peace in the region.

“It was quite surprising because there hasn’t been a U.S. administration that has been so focused on this issue in a while,” she said. “It was important that a U.S. president would focus his attention on this.”

Last summer, ahead of the presidential election, Grenell told Serbian Americans during the Republican Convention in Milwaukee, Wisconsin, that if Trump returned to the White House, he would make the Western Balkans a priority.

“Your future is with us, not with Russia or China. Your future is with America … America has a responsibility to keep pulling Serbia over,” he said.

So far in Trump’s second administration, that has not happened. But CSIS’ Ruy said that it was not impossible, as the administration has seized on issues that are not the subject of public focus, such as the recent mediation between Azerbaijan and Armenia.