文章显示，地缘政治正在把航道“武器化”。商船巨头Maersk的Vincent Clerc称，一些贸易路线已被前所未有地利用为施压工具；特朗普多次威胁控制巴拿马运河，也刺激了中国重新考虑尼加拉瓜运河等替代方案。伊朗战争背景下，胡塞武装对红海/曼德海峡的袭击使不少船舶改道好望角，绕行可达数千英里；曼德海峡一度需要船舶绕行超过8000英里，而2024年经好望角的日均通行量较上年增长77%。
不同国家对咽喉航道的依赖差异很大。对中国而言，台湾海峡是最重要的海上咽喉，承载41%的货物流量，而且中国有两个咽喉通道各自承担超过25%的海运贸易。文章还指出，巴拿马运河、苏伊士运河、霍尔木兹海峡、博斯普鲁斯/达达尼尔海峡等一旦中断，都会引发更广泛的能源、化肥和食品供应冲击；例如2023年红海扰动曾使油价每桶仅上升2至3美元，但本轮霍尔木兹危机已把燃料、航空煤油和化肥推入短缺。
Global seaborne trade is being magnified by the fragility of narrow maritime chokepoints. The Strait of Hormuz is only 30 miles (about 48 km) wide at its narrowest point, yet any disruption can hit the world economy. An Oxford University estimate says that, even before the Hormuz crisis, maritime chokepoints were affecting about $190bn of trade a year and causing $14bn of economic losses; for Hormuz itself, researchers say there is no alternative route for about 80% of the trade, helping push oil prices up by more than $40 since February.
The article shows geopolitics increasingly turning sea lanes into leverage. Vincent Clerc of Maersk says some routes have been weaponised in ways not seen before, while Donald Trump’s repeated threats to seize the Panama Canal have encouraged discussion of alternatives such as a Nicaragua Canal. Against the Iran war backdrop, Houthi attacks on the Red Sea and Bab el-Mandeb have pushed many ships to reroute around the Cape of Good Hope; some voyages must travel more than 8,000 miles farther, and average daily transits via that route rose 77% in 2024 versus a year earlier.
Dependence varies sharply by country. For China, the Taiwan Strait is the most important maritime chokepoint, carrying 41% of goods, and China has two chokepoints that each handle more than 25% of its seaborne trade. The paper also notes that disruptions to the Panama Canal, the Suez Canal, Hormuz, and the Turkish straits can cascade into energy, fertiliser, food security, and manufacturing; for example, Red Sea disruption in 2023 lifted oil prices by only $2 to $3 per barrel, but the current Hormuz crisis has already produced shortages of fuel, jet fuel, and fertiliser.