Welcome to the inquiry download from the BBC World Service. I'm Ruth

Alexander. Each week we bring you four expert witnesses answering one pressing

question from the news.

Recently we've made additions about the Saudi Crown Prince's ambitions

and Iran's revolutionary guard,

and those got us thinking. The missile takes off into the night sky like a small rocket, kicking up a dust cloud on the rocky land it's left behind.

The men behind the launch pad celebrate. Around a thousand kilometers away in Saudi Arabia's capital, Riyadh, the Saturday night

hum of activity is interrupted by a loud explosion.

Fragments of metal rained down into the car park of the city's international airport.

State media announces the Saudi Defence Force has intercepted and shot down a missile from Yemen, the third this year.

This could amount to an act of war, the Saudi crown prince said, blaming Saudi's old enemy,

Iran.

A dangerous claim, the Iranian foreign Minister retorted.

Tensions between these two Middle Eastern heavyweights

is at the highest it's been in years

as they flex their muscles around the region.

If the situation escalates into a full-blown conflict,

as some fear it might,

the devastating consequences would be felt around the world.

So in this inquiry we're going to look at the military capabilities of Saudi Arabia and Iran at their potential flash points and strategies

and at who else could get drawn into a war between the two. Our question this

week what would all-out war between Saudi Arabia and Iran look like?

...