$100 oil is not so easy to shake off.

According to Zhitong Finance APP, although crude oil flows in the Middle East have almost returned to levels seen before the US attack on Iran, global oil prices are still hovering above $100 per barrel, about 40% higher than before the conflict broke out.

Even last Friday's announcement by the Group of Seven (G7) and its partners that they would release up to 100 million barrels of emergency crude and diesel reserves failed to push oil prices lower.

On the contrary, a series of problems have combined to keep oil prices persistently high.

Traders worry that the unresolved war could reignite at any time, especially as the United States sends an additional aircraft carrier and more troops to the Persian Gulf.

Even maintaining the current stalemate carries risks, because Iran has already attacked some ships in its attempt to control the Strait of Hormuz.

At the same time, global crude oil inventories have been heavily depleted and are now at their lowest level in five years.

The ongoing war between Russia and Ukraine has blocked exports from many refineries that process crude into refined fuels, so refineries in other regions are willing to pay high prices to lock in the crude supply they need to keep operating continuously.

In addition, transporting crude out of the war zone through different shipping routes is itself extremely difficult, which also adds extra costs.

Haris Khurshid, chief investment officer at Karobaar Capital LP in Chicago, said: "We have lost supply, consumed inventories, and disrupted the ability to convert crude into refined products such as diesel. Getting oil moving again does not immediately solve any of these problems."

The following are the five major reasons why crude oil prices remain above $100 per barrel.

Panic factor

The market still fears that the war could escalate.

The United States and Iran remain deeply divided over the conditions for ending the war. Although the two sides have not yet returned to the full-scale hostilities seen this spring, they still occasionally launch attacks on each other.

Last month, a drone attack halted operations on Saudi Arabia's East-West oil pipeline, highlighting the persistent risks.

The war has roiled the market, and global crude benchmark prices have swung sharply.

Both Iran and the United States are trying to control the strategic shipping passage of the Strait of Hormuz.

Before the war broke out, about 20% of the world's crude oil shipments passed through the strait.

In addition, the Iran-backed Houthi armed group in Yemen has announced a blockade of Saudi Arabian shipping through the Bab el-Mandeb Strait in the Red Sea, putting another crude oil transport route at risk.

According to the latest news, the situation in Yemen has escalated again.

On the 4th local time, Houthi military spokesman Yahya Saree said in a statement that the group launched missile and drone attacks on two facilities of Saudi Aramco in Riyadh and the Khurais area.

The Houthis previously said that Saudi Arabia carried out a series of airstrikes on Yemen's Jawf province that day.

A day earlier, the Houthis also said they used ballistic missiles and drones to attack an oil facility in Riyadh, the Saudi capital, in response to recent Saudi attacks.

On the 4th, Rashad Muhammad al-Alimi, chairman of Yemen's Presidential Leadership Council and supreme commander of the armed forces, said in a televised speech from Riyadh, the Saudi capital, via Yemen National Television that after weeks of military mobilization, the Yemeni government had officially launched a large-scale military operation to recapture areas recently controlled by the Houthis.

He has ordered the armed forces, security agencies, and allied military forces to begin carrying out the operation plan.

Transport costs

Although some ships are still sailing through these chokepoints, disruptions to normal shipping have already driven up the cost of moving crude oil to market.

Moving crude out of the Strait of Hormuz currently still relies heavily on cross-strait shuttle transport, ship-to-ship transfers, and unconventional routes.

Freight rates for tankers carrying crude from the Persian Gulf to China have set records, exceeding $1.2 million per day, further increasing costs for consumers.

Senior crude oil analyst Xuyi Zhao said: "The core issue is that a recovery in supply volumes does not mean the entire supply system has fully returned to normal. Market pricing considers not only how much crude is being loaded onto ships, but also whether that crude can reach its destination safely, reliably, and at a relatively low cost."

Inventories badly hit

Although Middle East crude oil shipments are increasing, global inventories remain severely depleted because of the war.

According to data from consultancy Energy Aspects, global crude oil inventories currently stand at about 4.3 billion barrels, down by more than 400 million barrels since March, the first full month after the war broke out.

Meanwhile, after the initial shock of high oil prices, global crude oil demand has recovered.

Energy Aspects data show that total global crude oil demand is currently about 104.8 million barrels per day, an increase of 6.5 million barrels per day from the low during the war in May.

Fuel crisis

A recovery in crude oil flows cannot solve the global shortage of refined fuel supplies, such as diesel.

Exports from the world's two major refining centers, the Middle East and Russia, remain constrained.

As a result, refineries outside these two regions are doing everything they can to fill the supply gap, but that also means their equipment is running overloaded for prolonged periods, and any breakdown could lead to unplanned shutdowns.

To ensure a stable crude oil supply, these refineries are willing to pay whatever price is necessary.

Diesel has risen more than crude oil.

Inflation hedge

Central bank officials around the world are discussing how higher fuel prices are adding to inflationary pressure, which could ultimately lead to further increases in interest rates.

Traders say that as bond yields continue to rise, the crude oil market has once again become an inflation hedge in recent weeks.

Although this does not come from actual crude oil demand, it can still push oil prices higher.