(CNN)—With traffic slowing once again to a very low level in the Strait of Hormuz, the oil market faces the same pressures that led to the halting of supplies of millions of barrels per day since March.

But the world now lacks the main safety valve that helped mitigate the potential oil price shock last time: strategic crude oil inventories.

According to a blog post published by the International Monetary Fund on Wednesday, the deficit of about 4 million barrels per day from March to May was offset by a drawdown of crude oil inventories.

During the war in Iran, the International Energy Agency carried out the largest historical release of its emergency oil reserves, amounting to 400 million barrels.

China also managed to help alleviate the global shortage by reducing refinery output and relying on domestic inventories instead of purchasing from the market.

However, the IMF said that a large part of the mechanism designed to absorb supply shocks has been depleted.

The report said: "What mitigated the initial shock this time was that energy markets had room to maneuver to absorb the shock. If inventories are not replenished, the world will start from a weaker position when the next shock occurs."

In a research note released this week, Goldman Sachs also said that China may be moving to buy more crude oil now, as it looks to replenish its inventories with prices falling from their highs in May.