Many Americans are worried about ISIS attacks at home and overseas. But a greater threat to global stability is China's foreign policy.

For months, Americans have been riveted by headlines about Islamic State terrorist attacks across the globe. From Brussels to Lahore, it seems ISIS is the biggest thing going on overseas.

Yet a far greater threat to global stability is brewing in the South China Sea, where China has been building military bases on man-made islands and asserting maritime rights to some of the busiest global trade routes. Meanwhile, here in the United States, Chinese intelligence services have deployed an ever-widening network of spies.

Although not directly connected, both of these developments are manifestations of China’s new, expansionist foreign policy in the Pacific. If China and the United States don’t alter their trajectory, we could be slow-walking into another cold war—or setting the stage for a hot one.

Naval Officer Charged With Espionage

News broke over the weekend that a Taiwan-born Navy officer, Lt. Cmdr. Edward C. Lin, has been charged with passing military secrets to China. On its own, the discovery of a Chinese human intelligence operation in the United States is perhaps not all that remarkable, since by some estimates there are scores of Chinese spies in America, most of them engaged in corporate espionage.

If China and the U.S. don’t alter their trajectory, we could be slow-walking into another cold war.

But Lin’s case is different because he had access to sensitive military intelligence. Lin, who became a naturalized citizen in 2008 and speaks fluent Mandarin, served as a signals intelligence specialist for naval spy planes. “Signals intelligence” is how the U.S. military identifies the whereabouts of foreign military units, like submarines, and the methodology behind this work ranks among the U.S. armed forces’ most closely guarded secrets.

Although corporate spying by the Chinese might be common, the last time an active-duty member of the Navy was caught spying was in 1985, when John Walker, a Navy officer and submariner, was caught passing secrets to the Soviet Union as part of an elaborate spy ring that operated for 18 years.

That was during the Cold War, when spying between America and the Soviet Union was an open secret. The incident with Lin is the latest sign that a cold war with China could be on the horizon, especially as evidence mounts that China might be willing to risk a military conflict with America’s allies in Asia, and perhaps with America itself.

Chinese Spies Are Everywhere

News of Lin’s alleged espionage comes on the heels of recent remarks by the former head of the House Intelligence Committee that there are more foreign spies operating the United States than at any point in our history. In a recent speech at the Heritage Foundation, former Rep. Mike Rogers said foreign agents in the United States outnumber those of any previous period, including the Cold War. “They’re stealing everything. If it’s not bolted down, it’s gone,” Rogers said. “And if it’s bolted down, give them about an hour—they’ll figure out how to get that, too.”

There are more foreign spies operating the U.S. than at any point in our history.

In his remarks, Rogers noted the difference between Russian and Chinese operatives. The former tend to be trained professionals, he said, while the latter are often recruits with “a very specific goal of stealing a very specific piece of intellectual property,” making them harder to detect—and also more numerous.

Rogers isn’t the first to raise concerns about espionage in the United States. In 2012, former top CIA covert officer Hank Crumpton told CBS News there are more spies in America than during the peak of the Cold War. Crumpton, who ran counterintelligence inside the U.S. as chief of the CIA’s National Resources Division and served as deputy director of the CIA’s Counter-Terrorism Center, claimed major world powers, particularly China, have “very sophisticated intelligence operations, very aggressive operations against the U.S.”

China’s Military Outposts in the South China Sea

But espionage is just one aspect of China’s broader strategy to establish hegemony in the Pacific. A more visible sign of this strategy is the construction of artificial islands in the South China Sea on a string of disputed reefs and islets called the Spratley Islands. The man-made islands, which are more than 500 hundred miles from mainland China and now feature military-length runways and radar stations, are the main source of growing tension between China and its neighbors.

China’s man-made islands in the South China Sea now feature military-length runways and radar stations.

Over the past year, ongoing construction of the islands has prompted U.S. freedom-of-navigation patrols, designed to challenge China’s claim to them. Last month, the United States sent a carrier strike group, and the Navy has said it’s planning a third patrol near the artificial islands this month. In an effort to mollify anxious Pacific allies, we’ve also increased military aide to the Philippines and struck an agreement that would allow the Pentagon to use some military bases there to deploy U.S. troops for the first time in decades.

This issue isn’t going away. At a recent meeting of the G7, foreign ministers expressed concerns about “territorial disputes” in the East and South China Seas. Although not named outright, China’s artificial islands were clearly what the foreign ministers were referring to in a joint statement at the end of a meeting held in Hiroshima, Japan. The statement expressed “strong opposition to any intimidating, coercive or provocative unilateral actions that could alter the status quo and increase tensions,” and urged states to refrain from “land reclamations, including large scale ones,” and “building out outposts.”

Why such a strong statement? More than half of the world’s merchant fleet tonnage passes through the choke points surrounding the South China Sea. Robert Kaplan calls it “the throat of the Western Pacific and Indian oceans—the mass of connective economic tissue where global sea routes coalesce.”

The U.S. Government Isn’t Taking China Seriously

I spoke with Dr. Arthur Waldron, a professor of international relations at the University of Pennsylvania and a member of the highly classified Tilelli Commission, which evaluated the China operations of the CIA from 2000 to 2001. He told me China’s foreign policy shifted sharply in 2008. “It is now aggressive and expansionist,” he said, and if it doesn’t change, “it’s going to lead to war.”

China’s foreign policy shifted sharply in 2008. It is now aggressive and expansionist.

Waldron believes our inability to respond to China’s new posture has been a long time in the making. Under President Richard Nixon and Secretary of State Henry Kissinger, it was thought that the United States would partner with China as a strategic ally against the Soviet Union. For decades, we treated China as our most important Asian partner. But in recent years, the U.S. intelligence community has been astonished at the kind of aggressive intelligence operations China has launched at the United States, the vast number of people involved, and the sensitive targets they have chosen.

“We haven’t figured out how to react,” Waldron said. “One reason is that the administration is completely divided between people who are still holding the torch for a partnership and people who have had the scales fall from their eyes, and have realized that what we have now is something else. We can’t change their policy, but we can change ours.”

For its part, the Obama administration has worked to downplay concerns about China within the armed forces, and even imposed an unofficial gag order on military leaders over making South China Sea comments ahead of a nuclear summit in Washington that ended on April 1.

Waldron believes that China didn’t anticipate such strong resistance to its expansionist policy from other Asian countries, and that there might be an opportunity “for both sides to figure out whether we want to have another world war. This may be a pivot point.”

A recent editorial in the U.S. edition of the state-sponsored China Daily was rather blunt about where China stands: “Washington should know that the more provocative moves it makes against China, the more counter-measures Beijing will take,” the editorial stated. “Such an undesirable cycle may push both sides nearer confrontation and cause both to prepare for the worst-case scenario, potentially making it self-fulfilling.”