The Strait of Hormuz is a narrow waterway connecting the Persian Gulf to the Gulf of Oman, and is the only maritime passage from the Persian Gulf to the open sea, earning it the nickname ‘the master valve of the world’s oil reserves.’ The northern shore belongs to the Islamic Republic of Iran, where the important port of Bandar Abbas is located; the southern shore comprises the Musandam Governorate, an exclave of the Sultanate of Oman, and the United Arab Emirates. The strait is approximately 167 kilometers (90 nautical miles) long, with a width ranging from 39 kilometers (21 nautical miles) to 97 kilometers (52 nautical miles), narrowing to only about 33 kilometers at its narrowest point. In the central part of the strait, closer to the Iranian side, lies Qeshm Island, the largest island in the Persian Gulf, which belongs to Iran.
Strategic Importance
Because the countries along the Persian Gulf possess the world’s richest oil and natural gas resources, the Strait of Hormuz has become a critical chokepoint for global energy transportation, with its strategic importance ranking first among all maritime trade routes worldwide. In 2025, an average of approximately 20 million barrels of crude oil and petroleum products are transported through this strait daily, accounting for about one-quarter of global seaborne oil trade and equivalent to one-fifth of global petroleum liquid consumption. Saudi Arabia is the largest crude oil exporter through this strait, accounting for approximately 38% of the strait’s total crude oil flow; other exporting countries include Iraq, Kuwait, the UAE, Qatar, and Iran. Approximately 93% of Qatar’s and 96% of the UAE’s liquefied natural gas exports must pass through this strait to reach international markets, together accounting for about one-fifth of global LNG trade.
The oil transported through the strait primarily flows to Asian markets, with China, India, Japan, and South Korea being the four major importing countries, collectively receiving approximately 69% of the crude oil flowing through this strait. China alone depends on the Strait of Hormuz for about one-third of its oil supply. Alternative routes bypassing the Strait of Hormuz are extremely limited: currently, only Saudi Arabia’s East-West Pipeline (Petroline) and the UAE’s Abu Dhabi Crude Oil Pipeline (ADCOP) have bypass capability, with a combined spare capacity of approximately 3 to 5 million barrels per day – far insufficient to compensate for the transportation gap that would result if the strait were closed. For this reason, whether shipping through this strait remains unimpeded directly affects global energy security and economic stability.
Historical Development
The Strait of Hormuz connects the Persian Gulf with the Indian Ocean and has been a vital hub for East-West trade since ancient times. At the end of the 13th century, the Venetian traveler Marco Polo passed through this area on his return journey and recorded it in his travelogue. From the mid-14th century onward, the Kingdom of Hormuz (referred to in ancient Chinese texts as ‘Hulumosi’ or ‘Hulumosi’) rose along the strait, gradually monopolizing trade at the mouth of the Persian Gulf and becoming an important commercial hub between the Indian Ocean and the West Asian continent.
During the Yongle and Xuande periods of the Ming Dynasty, Admiral Zheng He led his treasure fleet on seven voyages to the Western Seas. Starting from the fourth voyage between 1413 and 1415, the fleet first reached the Kingdom of Hormuz at the mouth of the Persian Gulf, and every subsequent voyage included this destination. According to ‘The Overall Survey of the Ocean’s Shores’ by the interpreter Ma Huan and ‘The Overall Survey of the Star Raft’ by Fei Xin, who accompanied the voyages, Hormuz was described as a place where ‘all the people are wealthy,’ with thriving markets, and was considered a great nation among the foreign lands of the Western Seas. The ‘History of Ming’ further praised it as ‘a great nation of the Western Seas.’ During the Yongle and Xuande reigns, the Ming court maintained close relations with the Kingdom of Hormuz, with frequent exchanges of envoys. At that time, Hormuz was within the sphere of influence of the Timurid Empire, where Persian served as the lingua franca. Timur himself harbored ambitions of rebuilding the Mongol Empire, repeatedly detained Ming envoys, and planned an eastern expedition against the Ming Dynasty, though he ultimately died en route. Thus, the diplomatic exchanges between the early Ming Dynasty and the Timurid Empire and its vassal states hold profound significance in the history of Sino-foreign relations.
In the early 16th century, the Portuguese arrived in the East, and the Kingdom of Hormuz was conquered by Afonso de Albuquerque in 1507. From then on, the strait fell under the control of European colonial powers until it was recovered by Persia’s Safavid Dynasty in the 17th century.
