Israel's strikes on Iran, and Iran's response, caused a shudder on global financial markets on Friday.
The price of oil surged in particular, up 7% by mid-afternoon on Friday.
That has prompted worries that we could be facing another period of sharply higher energy prices, leading to a bout of higher prices for everything from petrol and food to holidays.
That is what happened after Russia invaded Ukraine three years ago, affecting people's lives around the globe.
How much have oil prices risen?
The attacks prompted an instant reaction on the markets.
Brent Crude – the main international benchmark – rose more than 10% before falling back to around $75 a barrel.
The price of oil rises and falls all the time in response to big geopolitical events, and the state of the global economy, so it is not a surprise to see oil prices reacting to the attacks.
However, the Brent crude price is still about 10% lower than a year earlier.
It is also well below the peaks seen in 2022 following Russia's invasion of Ukraine, when it spiked to nearly $130.
So will petrol and other prices go up?
When the wholesale oil price goes up, many people notice it first when it leads to higher petrol prices.
But more expensive energy also feeds through to higher prices for almost everything, from farming to manufacturing.
When it comes to food, higher energy costs can lead to higher prices on the shelf in many ways. It can make it more expensive to run farm machinery, to transport produce, and to process and package food.
However, that will only happen if energy prices stay high for a sustained period.
Even with petrol and diesel, rising crude prices only have a limited impact.
"A rough rule of thumb is a $10 rise in the oil price would add about 7p to the price at the pump," says David Oxley at Capital Economics.
However, this is not just an oil story, he cautions.
Many will remember the shock to prices that followed the beginning of the Ukraine conflict. That was in large part a response to higher gas prices, Mr Oxley says.
Many of us heat our homes with gas, and in the UK electricity prices are also set in relation to the gas price.
Gas prices have also risen after Thursday night's attacks. But the impact will feed through to households only slowly, if at all, says Mr Oxley, given the way the market works, including the role of the regulator, in capping prices.
