Who's paying for this war? First and foremost, the people of the Middle East, who are directly in harm's way. But who pays the financial cost if Iran continues to target the lifeline for the region's oil and gas? Maritime employers out of London are officially designating the Strait of Hormuz, the Gulf of Oman and the Persian and Arabian Gulf a "warlike operations area". We ask what that means and how much pain is to come.

The United States is far less reliant on the region's crude than the last time Iran mined the narrow waterway that ships one-fifth of the planet's supply. But how about Asia and Europe, which is bracing for another Ukraine war-style jolt in natural gas prices?

As France and the UK dispatch warships, how do NATO allies defend their interests without getting sucked into a war they didn't choose? How to handle a US president that's been pressuring them – with some success – to relax the switch to renewables and "drill, baby, drill"?

More broadly, how vulnerable are Gulf states, whose petrodollars fuel massive investments in artificial intelligence and whose skyscrapers in the sand depend on that other precious lifeline: water? How safe are the Arabian Peninsula's desalination plants, for instance, in these dangerous times?

Produced by François Picard, Rebecca Gnignati, Daniel Whittington, Ilayda Habip, Christophe Bauer.