Amid an energy crisis, the world is drawing on its oil reserves. Why doesn't Canada have any?

With war in the Middle East keeping the critical Strait of Hormuz fuel route closed, the international community is reaching into its oil reserves to fill the supply gap.

On Wednesday, the International Energy Agency (IEA) agreed to release 400 million barrels from its emergency reserves — its largest-ever release — in order to help ease a disruption of "unprecedented" scale, the IEA said.

That's drawing scrutiny of Canada's oil reserves — or, rather, its lack of them, as Canada is the only nation in the G7 that doesn't maintain a strategic reserve.

While Natural Resources Minister Tim Hodgson said on Wednesday that Canada would "do its part" to help contribute to the global oil supply, Conservative Party Leader Pierre Poilievre criticized the Liberal government for not having any reserves.

"Our stockpiles are at zero," Poilievre said during a heated debate with the prime minister during question period on Wednesday.

But why doesn't Canada have a strategic reserve, and what can the country do to help boost the world's supply? Here's what you need to know.

Canada is one of the 32 member countries of the IEA. The international body and its reserves were created in 1974 to co-ordinate an international response to an energy crisis at the time, started by the Arab oil embargo.

Member countries currently hold more than 1.2 billion barrels of public emergency oil stocks, with a further 600 million barrels of industry stocks held under government obligation.

The organization stipulates that members set enough oil aside to cover 90 days' worth of net imports — but Canada doesn't have to have reserves, because it's a net exporter. 

The U.S. is also a net exporter but keeps a strategic reserve anyway. The U.S. plans to tap some 174 million barrels of oil from its reserves starting next week.

While most of Canada's oil goes to the U.S., some from the Trans Mountain pipeline also supplies Asian markets, which face some of the greatest need as a result of the Strait of Hormuz shutdown.

Rory Johnston, a Canadian industry analyst and founder of Commodity Context, says that while dipping into the global reserves will help with supply a little, it's not enough to fill the gap left by the stoppage in the Strait, where some 20 million barrels would pass through per day before the war.

Johnston says the current situation shows how it might be time to rethink that rule about exporters not having a strategic reserve.

"If we had a [strategic petroleum reserve], we could have surge supply," Johnston said. "Because in this moment, Canada can't increase production in order to offset this disruption."