LONDON — The new coronavirus outbreak’s disruption to the world economy — with fewer planes flying, ships sailing and factories producing — has recently pushed down oil prices.

But now they are plummeting and taking world stock prices down with them.

What’s behind the dramatic price moves, and why is it shaking up the world markets? Here, NBC News takes a look at how we got to this point.

The coronavirus effect

With the viral epidemic already limiting economic activity in affected countries and reducing the demand for crude oil since late February, members of the OPEC cartel and the group’s key ally Russia met last week to discuss by how much each country should reduce output to address the crisis.

“The main reason why coronavirus is a threat to oil prices is that China is the main new consumer of oil in the world,” according to Cailin Birch, a global economist at the London-based Economist Intelligence Unit, which provides forecasts and advisory services to businesses.

China alone accounts for about a third of new consumption of oil each year, and Asia more broadly about 50 percent of new consumption, she added.

If the demand slows down in the region because people aren’t traveling or factories aren’t producing as a result of the coronavirus, oil prices will sink.

An all-out price war

When there has been an imbalance between supply and demand of oil in the past, oil-producing countries have agreed to reduce the supply to shore up prices, said Manouchehr Takin, an international oil and energy consultant who previously worked for OPEC.

But this time, OPEC — the Organization of the Petroleum Exporting Countries — and Russia failed to agree on a way to deal with the price fall caused by the virus.

Analysts told NBC News that Saudi Arabia had pushed for even deeper cuts to production, but Russia had disagreed and appeared unwilling to bear the brunt of more cuts.

Birch said among the reasons behind the lack of agreement could be that Saudi Arabia’s oil industry is entirely state-run, which means it is more able to make strategic decisions about matching production levels to its desired price. Meanwhile, Russia has powerful private sector interests meaning hits to the price of oil are harder to manage.

“Russia is also less willing to do anything that benefits the U.S. generally, given their poor relations and U.S. efforts to undermine Russia’s energy dominance,” she said, referring to American attempts to “sink” Russia’s European gas pipeline project.

Takin also said one interpretation of why Russia was hesitating to agree to further production cuts was that President Vladimir Putin may wish to squeeze the U.S. oil industry because, since it is led by the private sector, it is not well positioned to cope with falling oil prices.

The lack of agreement Friday has triggered a price war as nations race to capture the market share.

“That is a huge development for the market because the partnership between Saudi and Russia has been the only thing that’s been keeping a floor under oil prices,” Birch said.

“Now we have weakness on both the supply and the demand side of the scale, there’s very little propping them up,” she added.

What now?

The oil and gas sector should be very worried, according to analysts.

Many U.S. oil companies have borrowed money to dig for shale oil, and the fall in prices could force them to default on those loans, Takin said.

Additionally, the price war gives extra leverage to national oil companies such as Saudi Aramco, which are better placed to manage with less revenue for several months, he added.

However, falling oil prices mean lower prices at the pump — so consumers will be happy in the short term.

The Associated Press contributed to this report.