Chinese warships were recently spotted sailing close to the Aleutian Islands, just off the Alaskan coast. Meanwhile, naval boats have begun to dock at a Beijing-built military port in Cambodia.

While these two events took place on different sides of the globe, they’re both part of an important geopolitical development – one that may lead to global war.

That may seem a little alarmist. But as I explain in my book “Near and Far Waters: The Geopolitics of Seapower,” the dynamics playing out today as China seeks to surpass the U.S. as the world’s major sea power are reflected in the past – and have led to some of the world’s most consequential conflicts.

To understand the geopolitics of sea power, you need to understand two terms: “near waters” and “far waters.” Near waters are areas close to a country’s shoreline that are seen as important for its defense. Far waters are areas across the ocean that a country wants to be present in for economic and strategic interests.

But here’s the thing: The far waters of one country are the near waters of another, and that leads to tension. For example, the western Pacific is China’s near waters and the U.S.’s far waters – and both countries are engaged in a battle for strategic advantage there. Complicating matters, two or more countries may be competing for influence in the same near waters. In the western Pacific, China competes for dominance over smaller island fleets from, among other countries, the Philippines and Vietnam.

Changing tides

Competition over near and far waters changes over time. U.S. near waters are a strategic and fluid area, rather than a legal definition that covers the Eastern and Western seaboards – the latter extended by Hawaii far into the Pacific. It also covers parts of the Caribbean and the Aleutian Islands.

The U.S. gained control of its near waters throughout the 1800s and the first half of the 20th century. It culminated in a “destroyers-for-bases” deal during the early stages of World War II, which saw British military bases in the Caribbean and Newfoundland being transferred to Washington’s control. In return, the British were “gifted” old warships that were barely functional.

It was only later that the U.S. projected its influence into far waters across the Atlantic and the Pacific, especially through its success in the Second World War.

China, meanwhile, lost control of its near waters in the late 1800s as European colonial powers and the U.S. competed for access to China’s markets. It marked a humiliation for China, hampering economic growth and contributing to the collapse of traditional dynasties and the emergence of competing nationalist and communist politics – and eventually leading to civil war.

More than shipbuilding

China is a global economic power, and that requires controlling its near waters and building a presence in far waters.

Beijing sees this as a necessary and acceptable part of becoming a power equal to the U.S. But to the U.S. – the dominant naval power since World War II – the process represents a challenge to its presence in far waters.

China already has the largest navy in the world as measured by the number of ships. Over the past 15 years, China has built 131 ships that are capable of operating in far waters, while 144 are designed for near-water operations.

As of 2021, China was operating or fitting out two aircraft carriers, 36 destroyers, 30 frigates and nine large amphibious carriers – the type of vessels needed to truly challenge U.S. naval dominance.

These numbers are still dwarfed by the corresponding number of U.S. naval ships. But they are bigger than any other nation’s fleet, and without a doubt, China is developing a navy intended to project power into far waters.

But gaining sea dominance isn’t just about shipbuilding. The Chinese plan includes “island building” projects to establish a presence in the near waters of Asian countries, including the Philippines and Vietnam. Elsewhere, it seeks to use its economic might to entice countries away from Washington’s naval assistance.

Take Ream, a Cambodian military base in the Gulf of Thailand and former site of joint U.S.-Cambodian naval exercises. The base was in line for a refurbishment under a deal with the U.S. – an example of how Washington tries to maintain its presence in its Asian far waters.

But in a surprise move in 2020, Cambodia withdrew from the agreement.

Since then, funding from Beijing has provided for an upgraded base. There has been a continual Chinese presence at the Ream base in 2024, including the Chinese-funded construction of a pier and a large dry dock.

This naval presence serves China’s goal of defending its near waters. But it also adds to Beijing’s ability to project power into the far waters of the Indian Ocean, the Persian Gulf and the Red Sea.

A presence at Ream also gives China a prime position along a critical point of the “sea lines of communication,” the maritime routes through which much of global trade takes place. The nearby Malacca Strait is a key global choke point, through which US$3.5 trillion of trade passes annually – including a third of global trade, 40% of Japan’s and two-thirds of China’s.

Access to the Ream base in Cambodia puts China in the position to police those trade routes. China sees that policing role as positive and peaceful. The U.S. and other countries fear that China could use it to disrupt global trade – although it isn’t clear why China would do that when its economy relies on imports and exports.

Battle for influence

Ream isn’t an isolated example; China has been trying to gain power and influence across the Pacific for years.

Over the past decade, Beijing has developed strong economic and diplomatic relations with Pacific island nations, including a deal with the Solomon Islands that sparked Western concerns of China gaining a military naval presence there.

Of course, the U.S. is still a large and, for China, imposing presence through its bases in Japan and South Korea and its support of Taiwan. Washington has also started upping its efforts to outflank China among Pacific islands, inking a 2023 deal that would give U.S. ships “unimpeded access” to bases there.

But the geopolitics of sea power is a process, rather than determined by current events. As such, the ebb and flow should be viewed through the trajectory of naval presence over a number of years.

Which is why the presence of Chinese warships sailing close to Alaska is an important development.

It raises the prospect of China’s ability to project power into its far waters – and near waters of the U.S.

Albatrosses or hawks?

To be clear, China did not breach any international law by sailing close to the Aleutians. And U.S. officials seemingly played down the incident.

Still, it shows China has the ability and intent to take its naval rivalry with the U.S. into uncharted diplomatic waters, so to speak, and closer to the American coastline.

It represents a new stage in the sea power competition between the U.S. and China – and one we should all be concerned about.

In the past, the rise and fall of sea powers has played out through conflict in near and far waters and has led to major conflagrations. The Dutch fought the British and French in the far waters off the Indian coast in the 17th and 18th centuries, and a key ingredient of World War II was the challenge to British naval supremacy in its far waters in Asia and its near waters in northern Europe.

That isn’t to say that war in inevitable. It’s possible to address China-U.S. tensions in a way that accommodates China’s global ambitions without threatening or weakening other countries.

But that is a mutual duty, incumbent on policymakers in both Washington and Beijing. Relations between the two countries have, of late, been dominated by hawkish voices in both countries. But belligerence by either country when it comes to defending near or far waters would be a dangerous option.

Colin Flint does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.