What is the Strait of Hormuz, which Iran threatens to cut?

Iran is threatening to close the Strait of Hormuz after a US attack on its nuclear facilities, raising global concerns about the economic fallout from the escalating violence in the region. As the world's most critical oil transit point, the price of the "black gold" continues to rise, but Tehran could face more risks than benefits from the strategy, analysts predict.

Iran's parliament voted Sunday to close the strait, which carries 20 percent of the world's oil and a third of its liquefied natural gas. It is often described as the "most critical traffic point" in the world, and a decision to close it would severely restrict global oil supplies, including to some of Tehran's biggest allies.

Despite the parliamentary vote, the decision to proceed with this measure now lies with the National Security Council, and it is unclear whether Iranian leaders will risk antagonizing China, which is still highly dependent on oil passing through the strait and is Iran's main importer. Moreover, with oil revenues the main source of income for the Iranian state, this strategy seems even less likely.

However, if Iran goes ahead with closing the strait, it will also affect exports from other countries in the region, such as Saudi Arabia, Kuwait, Qatar and the United Arab Emirates. According to a note from S&P Global, this could remove more than 17 billion barrels of oil from the market, as well as 77 million tons per year of natural gas.

On the other hand, the US Energy Agency estimates that 84% of the oil and 83% of the natural gas that passed through the strait last year were destined for Asian markets, highlighting its importance for those countries.

In addition to China, countries such as India and South Korea are highly dependent on the flows that cross the strait, as opposed to the US or the EU, more desirable diplomatic targets for Tehran.

The strait is about 40 km wide at its narrowest point, but its navigable routes are less than two kilometres wide, forcing ships to pass through waters controlled by Oman and Iran.

Despite the tension surrounding Hormuz at various points in recent history, navigation through the strait has never been effectively cut off.