Chokepoints
T he journey from Shanghai to Rotterdam takes a container ship a month. Setting out at night, the vessel—a shadow amid glowing pleasure boats—begins by sliding past the Chinese city’s banks. Over the following fortnight it snakes through the Taiwan Strait and the South China Sea, threads the Strait of Malacca and crosses the Indian Ocean. Next come the Bab al-Mandab and the Suez Canal. Then the ship passes Gibraltar. After 30-odd days, it coasts through the English Channel, approaching its destination. Since the 1980s these waterways have been taken for granted. Now that the Strait of Hormuz is closed and the Red Sea hostage to the whims of Yemeni militias, it is clear that even a superpower with America’s might cannot guarantee safe passage in the face of drones, speedboats and mines. Shipping firms and world leaders are waking up to the fact that freedom of navigation is breaking down. Where, then, is international commerce most vulnerable? And where would be the most painful place for the next blockage? The importance of a single passage depends not just on the trade it carries, but on the available alternatives. For some passages—such as the Red Sea, where attacks by the Houthis have sent insurance rates rocketing—disruption is already priced in. We have, therefore, built a model to account for both how trade is conducted at present and where ships would go if access was cut off. It suggests that the closure of Hormuz, although extraordinarily expensive, is far from the worst scenario. Some 85% of all global trade by volume, and 55% by value, moves by sea. Here is a map of the most popular routes. Our model starts by finding the most efficient journeys between the world’s busiest ports. Then, using data on country-to-country trade, it calculates the share of seaborne traffic currently carried on each route (while assuming that adjacent countries trade mostly by land). This allows it to assess how trade would adapt if any route was blocked. The Taiwan Strait, for instance, is of enormous geopolitical importance. According to our model, it also carries 13% of seaborne trade by value. Yet dodging it requires only a small detour.
Alternative routes
Malacca is the world’s busiest strait by traffic value. Once again, however, convenient alternatives exist. Shutting the strait would increase the distance ships need to travel by just 9% on average.
Alternative routes
Blocked routes
More dramatic scenarios are possible. In a war over Taiwan, all the straits between Asia and Australia could be blocked, requiring an enormous detour around the Antipodes. The length of affected routes would increase by 58% on average. Other scenarios are harder to imagine, but would have brutal consequences. The closure of both the Strait of Gibraltar and the Suez Canal would make it impossible for ships to pass from the Mediterranean and Black Sea to other oceans.
Alternative routes
Blocked routesOur model assesses 14 scenarios in all. It finds that Hormuz is exceptional in one sense: no other single disruption has the potential to outright block (rather than reroute) so much trade. The Middle Eastern waterway surpasses both the Bosporus and Oresund straits—and the traffic they funnel to the Black Sea and the Baltic, respectively—in this regard. Moreover, our model may understate the waterway’s importance. It misses some important considerations, such as the composition of goods. Oil and liquefied gas cannot easily be transported by air or land. Nonetheless, other blockages would affect a far greater share of global trade—indicating they have the potential to cause still more trouble. Whereas our model suggests that 6% of maritime trade is affected by the closure of Hormuz, the closure of the Taiwan Strait would affect 13%; the Suez Canal, 16%; and the South China Sea, 24%. The very worst scenario—where all the straits from Malacca to Australia are closed—would affect 26%.
The Economist
America may have begun the war in Iran, yet Asia and Europe will suffer worse economic consequences. Uncle Sam would be similarly insulated with the blockage of many other waterways. The closure of the Korea strait would cause America the most trade problems, affecting 14% of its commerce but prompting only minor detours. For the European Union, the combined closure of Gibraltar and Suez would be catastrophic—affecting perhaps 40% of its seaborne trade, with 26% entirely blocked. China is also vulnerable. Closures in South-East Asia would affect more than 40% of its seaborne trade; closures of the Red Sea passages, over 25%. With time, human ingenuity finds a way around most obstacles. Pipelines can be expanded, trucking routes established and alternative supplies secured. But that is an inefficient process, which saddles the global economy with big, unnecessary costs. Whatever happens next, the events of the past month will prompt companies to build redundancy into their operations, to stockpile more, to use closer but less efficient suppliers and so on. They will be aware that the next time could be worse. ■
논증 분석
유형: comparative
핵심 주장
Strait of Hormuz 봉쇄가 큰 충격이지만, Taiwan Strait·Suez Canal·South China Sea 등의 봉쇄가 훨씬 더 많은 글로벌 교역량에 영향을 미치며, 복합적 봉쇄 시나리오는 세계 해상 무역에 재앙적 결과를 초래할 수 있다.
논리구조
- 전제: 전 세계 교역량의 약 85%(물량 기준), 55%(가치 기준)가 해상으로 이동하며, Strait of Hormuz 봉쇄와 Red Sea 불안정 등으로 항행의 자유가 실질적으로 위협받고 있다.
- 논거: The Economist의 모델은 298개 연안 도시 간 최적 항로와 BACI 무역 데이터를 결합해 각 해협 봉쇄 시 교역 영향을 정량적으로 산출했다.
- 진단: Taiwan Strait은 전 세계 해상 교역 가치의 13%를 담당하지만, 우회로가 존재해 봉쇄 시 항로 거리가 소폭만 증가한다; Strait of Malacca는 교통량 기준 세계 최대 해협이나, 봉쇄 시 평균 항로 거리가 9% 증가하는 데 그친다.
- 진단: Strait of Hormuz 봉쇄는 해상 교역의 6%에 영향을 미치는 반면, [[Taiwan Strait] 봉쇄는 13%, Suez Canal 봉쇄는 16%, South China Sea 봉쇄는 24%에 영향을 주어 Hormuz가 최악의 시나리오가 아님을 보여준다.
- 진단: 최악의 단일 시나리오는 Malacca부터 호주까지 동남아시아 전체 해협이 봉쇄되는 경우로, 전 세계 해상 교역의 26%에 영향을 미치고 항로 거리가 평균 58% 늘어난다.
- 논거: Gibraltar와 Suez Canal이 동시에 봉쇄될 경우 European Union의 해상 교역 최대 40%가 영향을 받고, 그 중 26%는 완전히 차단되어 EU에게 재앙적 결과를 초래한다.
- 논거: China는 동남아시아 해협 봉쇄 시 해상 교역의 40% 이상, Red Sea 봉쇄 시 25% 이상이 영향을 받아 지리적 취약성이 크다; 반면 America는 대부분의 시나리오에서 상대적으로 피해가 적다.
- 반론: 모델은 단기 충격만을 측정하며, 석유·LNG처럼 항공·육상 대체가 어려운 품목의 특수성이나 파이프라인 확장·대체 공급망 구축 등 장기 적응 역량을 과소평가할 수 있다.
- 결론: 해협 봉쇄 위험이 현실화됨에 따라 기업들은 중복 공급망 구축, 재고 확충, 근거리 비효율 공급업체 활용 등으로 대응하겠지만, 이는 글로벌 경제 전체에 불필요한 대규모 비용을 부과하는 비효율적 과정이다.
결론
Strait of Hormuz 봉쇄보다 South China Sea·Suez Canal·Taiwan Strait 등의 봉쇄가 세계 교역에 더 광범위한 피해를 주며, 복합 봉쇄 시나리오는 특히 European Union과 China에 치명적 결과를 초래할 수 있어 기업과 각국 정부는 공급망 복원력을 시급히 강화해야 한다.
Sources: BACI; European Space Agency; US National Centres for Environmental Information; NOAA Geosciences Lab/SOEST, University of Hawaii; The Economist
Methodology
Our model is based on calculating optimal routes between all big ports, and estimating the share of maritime commerce carried along each. To construct it, we first identified the location of 298 coastal cities in 128 countries and then calculated the optimal route between each pair, accounting for ice in polar regions and using detailed maps of the world’s oceans and canals.
We used a harmonised set of bilateral trade figures from BACI, a database, to roughly estimate the share of oceanic trade along each route. We assumed that most adjacent countries trade by land (with a few notable exceptions, such as China and India, which share a border in the Himalayas), and that bilateral trade by sea otherwise reflects bilateral trade overall. For countries with multiple ports, we assumed that the share of trade they ferried reflected their relative population size. And for countries bordering multiple oceans—where using ports on one coast would be vastly longer for a given route than ports on the other—we assumed they made the efficient choice.
To calculate each scenario, we blocked relevant parts of the world’s oceans, and recalculated optimal routes for all port-to-port trips. We cross-checked our estimated traffic volumes (both by port and for our key passages) against independent estimates. Our model deliberately looks at only the short-term impact.