Donald Trump多次主张美国可能放弃霍尔木兹海峡的海军安全保障，这比关税或贸易政策单项行动更深刻地改变了过去的美国做法。该海峡位于承载全球35兆美元货物贸易中四分之五的航道，并承载约全球石油流量的五分之一。自冲突升级后，船舶经过量从每日约135艘降至只剩零星船舶，且多为与伊朗相关；伊朗既优先处理自身出口，又将通过费提高到每次高达200万美元。欧洲和亚洲官员与分析师普遍视为对「航行自由」信心的直接冲击。
经济冲击已在能源与物流层面显现：伊拉克3月出口较去年同期日均量下滑约80%；沙特把原油改道经东西向管线运往红海，目前约7 million bbl/day（约111万 m³/day），接近满载，却在上月仍出现超过25%的出口下降。在交通受限下，伊朗据估每日至少可赚得约1.39亿美元油收入；同时，战区保险附加费从战前约船价0.15%升至部分航次高达10%。保险与战斗风险推高后，航运商仍避开霍尔木兹，任何重开可能都高度仰赖护航，且停火并不保证可即时恢复。
战略赌注已经不再只是在霍尔木兹。自1945年以来，美国海军一直是《联合国海洋法公约》规则的核心执行者，亦参与过1980年代伊朗—伊拉克「油轮战」及索马里反海盗行动。若华府缺位，阿联酋已推动联合国授权措施，英国也召集超过40个盟友采取非军事压力；联合国秘书长António Guterres警告最脆弱与最穷困人群受影响最大。若美方撤退，将加深其在其他关键瓶颈处威慑力下降的认知，可能让Xi Jinping较易在南海与东海推进中国主张。
Donald Trump’s repeated insistence that the United States might abandon naval security in the Strait of Hormuz is a deeper break with past U.S. practice than most tariff or trade-policy moves. The strait sits in shipping lanes for four-fifths of the $35 trillion global goods trade and carries about one-fifth of global oil flows. Since major war-stage escalation, traffic fell from about 135 vessels a day to only a handful, mostly Iran-linked, as Tehran prioritizes own exports and charges tolls of up to $2 million per transit. Analysts and officials in Europe and Asia see the move as a direct assault on confidence in freedom of navigation.
The economic impact is already showing in energy and logistics terms. Iraq’s exports reportedly dropped about 80% in March versus last year’s average daily level; Saudi Arabia is rerouting crude through its east-west pipeline to the Red Sea at roughly 7 million bbl/day (about 1.11 million m³/day), near capacity, yet still saw exports fall by more than 25% last month. Under constrained traffic Iran is estimated to earn about $139 million per day in oil revenue, even as extra war-risk insurance surged from about 0.15% of vessel value to as high as 10% for some voyages through the region. That rise plus the strike environment means operators avoid Hormuz, so reopening, if any, likely depends on escorts and may not be immediate after a ceasefire.
The strategic stakes now extend beyond Hormuz. Since 1945 the U.S. Navy has been central to enforcing the UN Convention on the Law of the Sea, including during the 1980s Iran-Iraq tanker war and anti-piracy missions off Somalia. In Washington’s absence, the UAE has pushed UN authorization, while the UK has gathered over 40 allies for non-military pressure; UN Secretary-General António Guterres warned the poor and vulnerable are most exposed. A retreat would also reinforce perceptions of weaker U.S. deterrence at other choke points, potentially easing Xi Jinping’s move to press China’s claims in the South China Sea and East China Sea.