If the US-Israeli ceasefire with Iran holds, it could offer the clearest hope of an end to the energy crisis since Iran’s Revolutionary Guards assumed control of the strait of Hormuz after the conflict began 40 days ago.

The deal is already looking shaky with Iran arguing late on Wednesday that Israel’s attacks on Lebanon breach it and state media claiming that the key waterway had again been closed.

Even if the temporary detente between White House and Tehran manages to hold and hundreds of tankers stranded in the Gulf start to transit once more, analysts fear that will not be enough to return the flow of oil, gas, chemicals and other vital items to pre-crisis levels.

How many ships remain in the Gulf?

An estimated 2,000 vessels – with about 20,000 seafarers onboard – have been trapped in the Gulf since the outbreak of the conflict, according to the UN. They include oil and gas tankers, bulk carriers and cargo ships as well as six tourist cruise liners.

Unable to pass through the strait to continue their journeys, most have remained anchored for almost six weeks, in some cases with dwindling supplies of food and water for their crews.

When will ship transits through the strait of Hormuz resume?

In the hours after the ceasefire announcement, there was not an immediate increase in the number of vessels passing through the strait.

A trickle of traffic has passed through in recent weeks – on most days only single digits – but this represents a tiny percentage of the average of 140 ships each day before the war.

Shipping analysts and owners have cautioned that even a temporary ceasefire does not provide a sufficient guarantee that it is safe to make the passage, particularly because Iran’s foreign minister has stated that transit would be under Iranian military management.

What needs to happen for more ships to start using the strait?

Many questions remain for shipowners and their captains over whether it is safe.

Iran has indicated it intends to continue operating the traffic control system it has put in place in the strait in recent weeks. This has included granting approval to “non-hostile vessels” – those determined as not having links to the US or Israel – and has required the sharing of large amounts of information on ownership, operator, cargo and previous voyages.

As part of a clearance process described as “fairly unsophisticated” by analysts, Iranian officials standing on Larak Island in the north of the strait have used binoculars to check the names of passing ships – and give approval to proceed.

To allow for visual verification, Tehran has tried to reroute ships to a more northerly corridor close to its coastline and away from traditional shipping lanes. However, this new route places even more constraints on an already congested waterway and could make it difficult for high numbers of ships to pass.

A successful ceasefire could also allow Iran and Oman to charge fees of up to $2m (£1.5m) a ship to pass through the strait. The requirement has been labelled “Tehran’s tollbooth” by shipping analysts at Lloyd’s List. It would allow Iran to continue to exercise control but it is unclear whether all shipowners would be willing to pay.

Fully loaded vessels are expected to be among the first to leave, rather than those that are empty and have not been able to reload.

Shipping analysts predict operators will gain confidence once a ship owned by a large European company has safely made the crossing. However, they caution that it is a different matter for empty ships to decide to enter the strait to load up at the region’s ports, and it is unclear when this may start to happen.

What does this mean for global energy supplies?

Energy markets have fallen sharply on the hope that millions of barrels of crude oil and gas trapped in the Gulf could soon help to relieve a crisis “more serious” than the energy flashpoints in 1973, 1979 and 2022 combined, according to the International Energy Agency.

But the disruption has been compounded by the forced shutdown of oil and gas production across the Gulf as storage facilities reached capacity. In addition, many key energy production sites have been damaged by drone attacks.

Experts have said it could take months or years to fully restore the Gulf’s energy production. Qatar has said that the significant damage sustained at its main production hub for liquified natural gas (LNG) after an Iranian strike had reduced its capacity by 17%. Officials predicted it could take between three and five years to repair.

Wood Mackenzie, an international oil consultancy, assumes that if Qatar began restarting its remaining LNG capacity next month, it would take until the end of August for its undamaged capacity to return to service. “It is unclear if QatarEnergy would consider doing this during a ceasefire, however,” said Tom Marzec-Manser, a gas analyst at the company.

The Gulf refineries that provide more than half of Europe’s jet fuel have also been damaged, and could take months to return to normal.

Willie Walsh, director general of Iata, which represents the airline industry, told reporters in Singapore that even if the strait of Hormuz were to remain open “it will still take a period of months to get back to where supply needs to be, given the disruption to the refining capacity in the Middle East”.

So can we expect energy market prices to fall?

Only if the ceasefire holds and even then not by much, and perhaps not for long. Oil and gas markets reacted with relief to initial reports of a ceasefire, with a sharp slump in global wholesale prices. But analysts have predicted prices could begin to drift higher again as the global energy supply squeeze intensifies in May and June.

The international crude benchmark opened at just below $95 (£71) a barrel on Wednesday morning, down from about $110 a barrel the day before, while European gas prices opened almost 20% lower at under €43 (£37) per MWh. These prices are still well above pre-crisis levels, meaning higher costs in the global economy. There are particular concerns about jet fuel prices that normally move in tandem with oil prices, but which have more than doubled since the Iran conflict.

Traders are also expected to price in an continuing “geopolitical risk premium” to reflect uncertainty over whether the ceasefire will hold or conflict may resume. This will keep energy market prices “significantly higher than before the conflict”, according to Tamas Varga, an analyst at PVM Oil, part of the Icap group. “Consequently, a return to sub-$70 levels is highly improbable, at least over the next year or two,” he said.

When will the Gulf’s oil and gas exports return to normal?

Maybe never. Even if the strait remains open, and production and refining capacity is restored to normal, many countries will be rethinking their approach to energy because of the crisis.

In Asia, in particular, the Gulf crisis has exposed many countries to the risk of relying too heavily on a single region for energy supplies, with many likely to diversify their sources in the future.

For those relying on the Gulf for future energy supplies there could be higher costs if Iran extracts transit fees from tankers over the long term, and a greater risk premium to pay tanker operators to use this route. This means Gulf imports may be reduced in favour of oil and gas producers in the Americas, for example.

There is likely to be a greater interest in nuclear power and renewable energy sources too, which, combined with a shift to electrified transport and greener industry, could help countries to cut their reliance on fossil fuels entirely.

Shipping analysts caution that it can take a long time for maritime companies to regain the confidence to return to dangerous routes. Few commercial shipping operators had returned to the Red Sea by January, a year after Houthi rebels in Yemen said they had stopped targeting ships. They have preferred the longer and more expensive – but more predictable – route around the Cape of Good Hope, at the southern tip of Africa.