Maritime Chokepoints Are Becoming the New Geopolitical Main Stage

"Whoever rules the waves rules the world."

By this he meant not only war fleets, but above all the key points of the shipping routes. Whoever controls these so-called chokepoints can starve out entire economies without firing a shot².

In the past, the world's sea connections enjoyed a stability secured by Western hegemony. Today, however, in an era of renewed great-power rivalries, the oceans and their bottlenecks are turning into the main stage of geopolitical conflict. Events such as the blockage of the Suez Canal in 2021 or the recent attacks in the Red Sea have exposed the vulnerability of trade routes. Great powers like China and regional actors such as Iran or rebel groups (for instance the Houthis in Yemen) increasingly use maritime bottlenecks as leverage to extract political or economic advantage. The open sea is thus developing, figuratively speaking, from a free "blue ocean" into a contested zone.

In what follows I analyse how the shift in the world order has raised the importance of maritime chokepoints, which strategic bottlenecks are currently most in focus and who the winners of this development are. A case study on China's creeping blockade in the South China Sea finally illustrates the new dynamic.

The Shift in the World Order: From Balance to Bloc Formation

Before: Hegemonic order and guaranteed sea lanes

In the second half of the 20th century, and especially after the Second World War, the US and its allies (for example NATO) provided a largely stable maritime security system. The US Navy acted as the "policeman of the seas" and ensured that the most important trade routes stayed open^{3, 4}. Historically, other sea powers had previously taken on this role (Portugal in the 16th century, the Netherlands in the 17th, Great Britain in the 18th and 19th). From the start of the 20th century it was primarily the United States that secured the sea lanes, a costly task, but a worthwhile one for the hegemon, since it benefited most from free trade itself.

Under this US-led system, underpinned by international agreements such as the UN Convention on the Law of the Sea (UNCLOS), maritime chokepoints generally stayed open for civilian traffic. Clear power relations deterred potential troublemakers, and incidents (such as piracy) were contained by multinational naval operations. Even during the Cold War, individual crises aside, there were no deliberate blockades of important straits by the superpowers. The "balance of terror" enforced restraint, and economic interdependence did its part to avoid open conflict at sea. In short: stable power relations and a recognised ordering power guaranteed the security of maritime trade flows⁵.

Now: A multipolar world and the return of the "zone of violence" at sea

With the rise of new powers and the erosion of the old order, the picture has turned. We live in a multipolar world in which no single power can, and in part will, still secure all the world's sea lanes. International regimes have been weakened: institutions such as UNCLOS still exist, but their enforcement often fails in the face of power politics. One example is the 2016 ruling of the Hague arbitration court, which declared China's extensive claims in the South China Sea illegal. Beijing ignores it to this day^{6, 7}.

The constitutional lawyer Carl Schmitt once described spaces free of rule as a "zone of violence". Exactly this dynamic is now returning to the world's oceans: open sea areas without an effective ordering authority become the stage for power struggles in which rules and boundaries are re-calibrated or disregarded. Four central drivers heighten the geopolitical volatility of maritime chokepoints:

Chokepoints in the Current World Situation

More than 50% of global seaborne trade is currently potentially vulnerable in a few regions that are crystallising into geopolitical tension zones. Many global goods flows concentrate on a handful of central bottlenecks. About half of all significant maritime chokepoints lie in Asia, which underlines the key role of the Indo-Pacific region. But Europe and the Middle East are exposed as well.

The simultaneous rise in geopolitical tensions at precisely these nodes (the Middle East, the Indo-Pacific, the Black Sea region) hints at why maritime chokepoints are becoming the new main stage of world politics. Even in the short term, disruptions lengthen delivery times; in the long term, companies could be forced to fundamentally restructure their supply chains, a tectonic shift in world trade.

New Winners: Who Benefits from the New Maritime Geopolitics

The shift in the balance of power at sea creates new winners. Actors who can capitalise on the importance of the chokepoints or strengthen their position:

States with sea access and fleet capacity

Countries with strong naval forces and merchant-fleet capacity can project power and defend their interests in the new situation. China above all: in just two decades the People's Republic has built a vast navy.

Many units are smaller and shorter in range than those of the U.S. Navy, yet China's ability to show presence in Asian waters increasingly deters rivals. India, Japan and other littoral states are strengthening their navies as well. Overall, a new maritime arms race is taking shape: whoever has access to the sea and invests in ships gains strategic room for manoeuvre. At the same time, the US retains the global upper hand in terms of striking power despite its smaller ship count, thanks to aircraft carriers, submarines and bases around the world. But its lead is shrinking in relative terms.

States at strategic chokepoints

Geography is once again becoming geopolitics. Countries that control important straits or lie along them gain bargaining power.

Overall, the principle holds: proximity to chokepoints gives states leverage in world politics. They can levy transit fees, enter alliances or, in the extreme, threaten closure. The new importance of the straits gives these countries a stage on which to bring their otherwise limited power to bear globally.

Private actors

Not only states, but also the private sector and non-state actors are part of the maritime power shift, in part as beneficiaries. Shipping lines and logistics giants are among them: in times of crisis the market often concentrates even more strongly on a few large companies. When small shipping providers avoid risky routes, groups such as Maersk, MSC or COSCO step in, having the capital and the fleets to serve unsafe waters as well. They can charge high freight rates for their services; in 2021/22, for instance, container prices exploded, handing large liner companies billions in profit.

Insurers are another winner: war-risk premiums rise sharply during conflicts at sea. After the Houthi attacks, the insurance premium per transit nearly doubled in 2025¹⁶. Security firms benefit too: demand is rising for private armed onboard teams, maritime security consultants and escort vessels. Finally, commodity and financial speculators emerge as indirect winners: every shortage drives prices up, and whoever bets on it or controls alternative sources of supply pockets the gains.

Actors who deliberately exploit instability

Among the invisible winners are those who actively stoke instability to pursue their own goals. Revisionist states such as China, Russia or Iran have recognised that they can harm the established powers and secure their own advantages by pinpricks at maritime chokepoints¹⁷. They often operate in the grey zone: in 2022 Russia deployed drones to sabotage Ukrainian port infrastructure and obstruct grain exports across the Black Sea. Iran uses proxies (the Houthis) to create unrest on one of the most important oil routes.

Non-state violent actors likewise profit from chaos: in 2023, 120 pirate attacks were recorded worldwide, and any conflict that pulls navies away can push such figures higher. In 2023 the Houthi rebels openly justified their attacks on international ships "in solidarity with Palestine", placing local violence in a global context. For such actors, maritime chokepoints are attractive targets, because this is where the vulnerability of the great powers is highest.

Case Study: China Selectively Blockades the South China Sea

To close, a scenario that makes the dynamics described above tangible. The South China Sea (SCS) already counts as one of the most contested maritime spaces in the world. The question is: what if China effectively takes control of this sea without open war, step by step, administratively disguised?

The South China Sea is geostrategically extremely important. About 3 trillion US dollars in goods are transported through this maritime region every year. The sea also holds rich fishing grounds and potential oil and gas deposits. Several littoral states, such as Vietnam and the Philippines, raise claims that overlap with China's far-reaching claim (the "nine-dash line", around 90% of the SCS). An international arbitration court in The Hague dismissed China's historical territorial assertion as unfounded in 2016.

Beijing, meanwhile, has created facts on the ground: since 2013, China has reclaimed more than 3,200 acres of new land in the SCS and built bases there with ports, runways and radar stations. Many of these artificial islands are now equipped with military installations such as anti-aircraft and anti-ship missiles.

China pursues a gradual expansion of its influence in the grey zone below the threshold of war (the "salami tactic"). In this way Beijing extends its control without provoking open war:

Regional effects

Littoral states such as Vietnam, the Philippines or Malaysia feel direct disadvantages. Their fishermen lose income when China's fleets occupy traditional fishing grounds. Planned oil and gas projects have been halted for fear of Chinese intervention; in 2018, for example, Vietnam broke off a major offshore drilling project under pressure from Beijing, which cost the firms involved hundreds of millions of US dollars¹⁹.

Global consequences

Nearly half of the world's crude oil and a significant share of LNG and merchandise trade flows through the SCS. A severe disruption of this route would send global supply chains reeling. Insurers could declare the area high-risk, similar to the Gulf of Aden, where after 2008 premiums per transit exploded from around 20,000 to 150,000 USD. A one-week closure of the Strait of Malacca would, by some estimates, cause more than 60 million USD in additional costs.

International law vs. power politics: China's disregard of the Hague arbitration award and the enforcement of its claims by fait accompli set a dangerous precedent: the rule-based order erodes when the law of the strongest sets the tone. At the same time, the alliance system is being put to the test, since the US must stand by its ally or risk a loss of trust across Asia.

Power shift and economic risks: Were China to bring the SCS de facto under its control, the balance of power in Asia would shift in its favour. The US Navy would be pushed out of China's vicinity; neighbours would have to accommodate Beijing or rearm massively. Until now, international norms and the US presence guaranteed open sea lanes; in future a single power could control access. Ultimately, the SCS stands symbolically for whether the world order in the 21st century will be shaped by law or by power, a course-setting decision of global consequence.