The Locked Sea
China has built the world's largest navy. It has not escaped its geography. Why the island chains, the Malacca Strait, and a rearming Japan mean Beijing's maritime power is more constrained than it appears.
Key Takeaways
China's naval expansion is real but its strategic problem is structural. The island chains that cage it cannot be solved by shipbuilding alone.
The Malacca Dilemma remains unresolved. Eighty percent of China's oil imports flow through a single chokepoint it does not control and cannot defend in a conflict.
Japan's rearmament is accelerating the squeeze. Tokyo's new long-range strike capability and deepened US alliance directly threaten China's ability to operate beyond the First Island Chain.
Beijing's anxiety is the tell. China's furious response to Japanese rearmament reveals a power that knows its geographic position is weak, not one confident in its own strength.
The Geographic Logic
China is not a maritime nation in the way Britain or the United States are. It is a continental power with a coastline, and that coastline is hemmed in by one of the most strategically consequential chains of islands on earth.
The First Island Chain runs from Japan in the north, through the Ryukyu Islands, past Taiwan, and down through the Philippines to the Indonesian archipelago. It sits less than two hundred miles from China's coast at its closest points. Every significant body of water China's navy operates in — the Yellow Sea, the East China Sea, the South China Sea — lies behind this chain. To reach the open Pacific, Chinese vessels must pass through narrow straits: the Miyako Strait, the Luzon Strait, or the Bashi Channel. All of them are observable, trackable, and in a conflict, closeable.
Beyond lies the Second Island Chain, running through the Mariana Islands to Guam. This is the outer boundary of American power projection in the region and the horizon of Chinese naval ambition. The space between the two chains is the contested operating ground that geography has made structurally hostile to Chinese interests.
The Current Situation
China has built the world's largest navy by vessel count. Its third aircraft carrier, Fujian, was commissioned in November 2025, the first outside the US Navy to use electromagnetic catapult launch systems. By raw numbers, the PLA Navy is formidable.
Numbers do not resolve geography. China's three main fleet home ports sit at Qingdao in the north, Ningbo on the central coast, and Zhanjiang in the south, with the carrier base at Sanya on Hainan. Every major surface combatant must transit the First Island Chain to reach open ocean. In peacetime this is manageable. In a conflict it becomes a fatal constraint.
On the other side of that chain, Japan is rearming at a pace not seen since 1945. Under Prime Minister Takaichi, Tokyo has approved a record 9 trillion yen defence budget for 2026 and is deploying long-range Type-12 missiles with a reach of one thousand kilometres, placing Chinese naval bases within range from Japanese territory. When Takaichi declared in November that a blockade of Taiwan could constitute a survival-threatening situation for Japan, Beijing responded with coast guard deployments to disputed islands, formal protests, and a carrier group sent near Japan in December. Chinese carrier-based jets reportedly conducted radar lock-ons against Japanese aircraft during that deployment.
The aggression was not confidence. It was anxiety.
The Strategic Divergence
China's problem has two layers, and they compound each other.
The first is the island chain problem. The First Island Chain is held substantially by US treaty allies: Japan, the Philippines, and effectively Taiwan. Japan's Ryukyu Islands alone stretch over a thousand kilometres, forming a near-continuous barrier. The Miyako Strait, China's primary deep-water passage to the Pacific, is flanked by Japanese territory on both sides. Japan's new strike capability means Chinese naval movements through these passages can now be contested by Japanese forces without American intervention being required.
The second is the Malacca Dilemma. Roughly eighty percent of China's oil imports and two thirds of its total maritime trade transit the Strait of Malacca. The waterway is less than three kilometres wide at its narrowest point, controlled by no friendly power, and within interdiction range of US and Indian naval forces. China has spent two decades attempting to solve this through overland pipelines via Myanmar, Pakistan, and Central Asia. None come close to replacing Malacca. The Myanmar pipeline is disrupted by civil war. The Pakistan corridor faces chronic instability. In a conflict, China's economic lifeline could be severed at a point it cannot defend, by a navy it cannot match in those waters, from bases it does not have.
Together, these two constraints mean that China, despite building the world's largest navy, cannot reliably project force beyond its near seas, cannot guarantee its energy supply in a conflict, and is encircled by adversaries from Japan and South Korea in the north to Vietnam and India along its trade routes south.
What This Locks In
Japan's rearmament is now a structural fact. Beijing cannot reverse it.
The First Island Chain remains a hard geographic constraint regardless of how many carriers China builds.
The Malacca Dilemma is no closer to resolution. Pipeline diversification offers partial mitigation at best.
China's assertiveness in the South China Sea, toward Taiwan, and in its response to Japan is partly an attempt to manage the anxiety that comes from knowing this position. The louder Beijing is, the more clearly it signals the depth of the problem.
A Taiwan conflict would not be a contained political crisis. It would activate every one of these vulnerabilities simultaneously.
Strategic Implications
For defence and security planners: Sea denial is a more achievable objective for the US-Japan alliance than sea control is for China. Japan's long-range strike capability changes the calculus at the Miyako Strait specifically. Planners should update assumptions about how early Chinese carrier groups can be detected and constrained in their transit corridors. The defensive architecture of the First Island Chain is hardening faster than Chinese power projection capability is growing.
For corporate and supply chain risk: The Malacca Strait carries one third of global maritime trade. Any escalation in the Taiwan Strait or South China Sea does not produce a contained regional disruption. It produces a global supply chain crisis. Energy, semiconductors, consumer goods, and raw materials all transit these waters. Contingency planning should treat Malacca disruption risk as structurally linked to Taiwan Strait tension, not as a separate scenario.
For financial and sovereign risk: China's demographic trajectory combines with its geographic exposure to create a risk profile significantly worse than headline GDP figures suggest. A shrinking working-age population, a collapsed birth rate, and unresolved property debt are structural drags that compound the geographic problem. The pressure on Xi to act on Taiwan before the window narrows comes not from strength but from the awareness that time may not be on China's side. Investors pricing China as a confident ascending power may be systematically underweighting the fragility underneath.
What to Watch
Japan's missile deployment timeline. If Type-12 and Tomahawk deployments proceed on schedule through 2026, the First Island Chain becomes qualitatively stronger and the cost of any Taiwan operation rises sharply. If political resistance or supply bottlenecks cause delays, that window stays open longer.
Chinese carrier operations beyond the First Island Chain. Routine blue-water deployments into the Western Pacific would signal growing confidence in managing the transit problem. Episodic, short-range deployments signal the geographic constraint is holding.
Malacca diversification progress. The Myanmar pipeline is the most credible near-term alternative. Stability there could increase throughput meaningfully. Continued civil war leaves China's Malacca exposure structurally unchanged.
South China Sea friction with Vietnam and the Philippines. Both countries sit astride China's main trade approaches and are moving closer to US and Japanese security frameworks. Escalation would sharpen trade route vulnerability and force ASEAN states to choose sides.
Beijing's domestic signalling on Taiwan. Aggressive external rhetoric combined with internal economic and demographic pressure is the combination that produces miscalculation. Watch state media framing of Taiwan timelines alongside economic data releases. A leadership under pressure at home that believes its strategic window is narrowing is the highest-risk configuration.
The Locked Sea
China has built the world's largest navy. It has not escaped its geography. Why the island chains, the Malacca Strait, and a rearming Japan mean Beijing's maritime power is more constrained than it appears.
Key Takeaways
China's naval expansion is real but its strategic problem is structural. The island chains that cage it cannot be solved by shipbuilding alone.
The Malacca Dilemma remains unresolved. Eighty percent of China's oil imports flow through a single chokepoint it does not control and cannot defend in a conflict.
Japan's rearmament is accelerating the squeeze. Tokyo's new long-range strike capability and deepened US alliance directly threaten China's ability to operate beyond the First Island Chain.
Beijing's anxiety is the tell. China's furious response to Japanese rearmament reveals a power that knows its geographic position is weak, not one confident in its own strength.
The Geographic Logic
China is not a maritime nation in the way Britain or the United States are. It is a continental power with a coastline, and that coastline is hemmed in by one of the most strategically consequential chains of islands on earth.
The First Island Chain runs from Japan in the north, through the Ryukyu Islands, past Taiwan, and down through the Philippines to the Indonesian archipelago. It sits less than two hundred miles from China's coast at its closest points. Every significant body of water China's navy operates in — the Yellow Sea, the East China Sea, the South China Sea — lies behind this chain. To reach the open Pacific, Chinese vessels must pass through narrow straits: the Miyako Strait, the Luzon Strait, or the Bashi Channel. All of them are observable, trackable, and in a conflict, closeable.
Beyond lies the Second Island Chain, running through the Mariana Islands to Guam. This is the outer boundary of American power projection in the region and the horizon of Chinese naval ambition. The space between the two chains is the contested operating ground that geography has made structurally hostile to Chinese interests.
The Current Situation
China has built the world's largest navy by vessel count. Its third aircraft carrier, Fujian, was commissioned in November 2025, the first outside the US Navy to use electromagnetic catapult launch systems. By raw numbers, the PLA Navy is formidable.
Numbers do not resolve geography. China's three main fleet home ports sit at Qingdao in the north, Ningbo on the central coast, and Zhanjiang in the south, with the carrier base at Sanya on Hainan. Every major surface combatant must transit the First Island Chain to reach open ocean. In peacetime this is manageable. In a conflict it becomes a fatal constraint.
On the other side of that chain, Japan is rearming at a pace not seen since 1945. Under Prime Minister Takaichi, Tokyo has approved a record 9 trillion yen defence budget for 2026 and is deploying long-range Type-12 missiles with a reach of one thousand kilometres, placing Chinese naval bases within range from Japanese territory. When Takaichi declared in November that a blockade of Taiwan could constitute a survival-threatening situation for Japan, Beijing responded with coast guard deployments to disputed islands, formal protests, and a carrier group sent near Japan in December. Chinese carrier-based jets reportedly conducted radar lock-ons against Japanese aircraft during that deployment.
The aggression was not confidence. It was anxiety.
The Strategic Divergence
China's problem has two layers, and they compound each other.
The first is the island chain problem. The First Island Chain is held substantially by US treaty allies: Japan, the Philippines, and effectively Taiwan. Japan's Ryukyu Islands alone stretch over a thousand kilometres, forming a near-continuous barrier. The Miyako Strait, China's primary deep-water passage to the Pacific, is flanked by Japanese territory on both sides. Japan's new strike capability means Chinese naval movements through these passages can now be contested by Japanese forces without American intervention being required.
The second is the Malacca Dilemma. Roughly eighty percent of China's oil imports and two thirds of its total maritime trade transit the Strait of Malacca. The waterway is less than three kilometres wide at its narrowest point, controlled by no friendly power, and within interdiction range of US and Indian naval forces. China has spent two decades attempting to solve this through overland pipelines via Myanmar, Pakistan, and Central Asia. None come close to replacing Malacca. The Myanmar pipeline is disrupted by civil war. The Pakistan corridor faces chronic instability. In a conflict, China's economic lifeline could be severed at a point it cannot defend, by a navy it cannot match in those waters, from bases it does not have.
Together, these two constraints mean that China, despite building the world's largest navy, cannot reliably project force beyond its near seas, cannot guarantee its energy supply in a conflict, and is encircled by adversaries from Japan and South Korea in the north to Vietnam and India along its trade routes south.
What This Locks In
Japan's rearmament is now a structural fact. Beijing cannot reverse it.
The First Island Chain remains a hard geographic constraint regardless of how many carriers China builds.
The Malacca Dilemma is no closer to resolution. Pipeline diversification offers partial mitigation at best.
China's assertiveness in the South China Sea, toward Taiwan, and in its response to Japan is partly an attempt to manage the anxiety that comes from knowing this position. The louder Beijing is, the more clearly it signals the depth of the problem.
A Taiwan conflict would not be a contained political crisis. It would activate every one of these vulnerabilities simultaneously.
Strategic Implications
For defence and security planners: Sea denial is a more achievable objective for the US-Japan alliance than sea control is for China. Japan's long-range strike capability changes the calculus at the Miyako Strait specifically. Planners should update assumptions about how early Chinese carrier groups can be detected and constrained in their transit corridors. The defensive architecture of the First Island Chain is hardening faster than Chinese power projection capability is growing.
For corporate and supply chain risk: The Malacca Strait carries one third of global maritime trade. Any escalation in the Taiwan Strait or South China Sea does not produce a contained regional disruption. It produces a global supply chain crisis. Energy, semiconductors, consumer goods, and raw materials all transit these waters. Contingency planning should treat Malacca disruption risk as structurally linked to Taiwan Strait tension, not as a separate scenario.
For financial and sovereign risk: China's demographic trajectory combines with its geographic exposure to create a risk profile significantly worse than headline GDP figures suggest. A shrinking working-age population, a collapsed birth rate, and unresolved property debt are structural drags that compound the geographic problem. The pressure on Xi to act on Taiwan before the window narrows comes not from strength but from the awareness that time may not be on China's side. Investors pricing China as a confident ascending power may be systematically underweighting the fragility underneath.
What to Watch
Japan's missile deployment timeline. If Type-12 and Tomahawk deployments proceed on schedule through 2026, the First Island Chain becomes qualitatively stronger and the cost of any Taiwan operation rises sharply. If political resistance or supply bottlenecks cause delays, that window stays open longer.
Chinese carrier operations beyond the First Island Chain. Routine blue-water deployments into the Western Pacific would signal growing confidence in managing the transit problem. Episodic, short-range deployments signal the geographic constraint is holding.
Malacca diversification progress. The Myanmar pipeline is the most credible near-term alternative. Stability there could increase throughput meaningfully. Continued civil war leaves China's Malacca exposure structurally unchanged.
South China Sea friction with Vietnam and the Philippines. Both countries sit astride China's main trade approaches and are moving closer to US and Japanese security frameworks. Escalation would sharpen trade route vulnerability and force ASEAN states to choose sides.
Beijing's domestic signalling on Taiwan. Aggressive external rhetoric combined with internal economic and demographic pressure is the combination that produces miscalculation. Watch state media framing of Taiwan timelines alongside economic data releases. A leadership under pressure at home that believes its strategic window is narrowing is the highest-risk configuration.