For the first three weeks of this month, Israel and Iran appeared to be on the brink of an all-out war.

The world held its breath as the Middle East’s military superpowers headed towards a conflagration that would have ignited the entire region, and quite possibly triggered world war three. 

Then, just as suddenly, it was all over. 

Israel bombed an Iranian consulate. Iran retaliated with hundreds of missiles and drones against Israel, but didn’t kill anyone; then Israel struck back with a bombing raid just small enough for the Iranians to pretend it had not happened.  

World war three, it turned out, was more like a duel between 18th-century gentlemen:

Both men had fired their pistols, honour was defended, and everyone could go home. 

What on earth was Tehran thinking? 

In this episode of Defence in Depth, Roland Oliphant, senior foreign correspondent, asks the question: would a war with Israel rally Iranians to the flag - or would it be the last straw that would see them finally overthrow the regime?

Watch Roland’s video analysis above. Find more episodes of Defence in Depth on The Telegraph’s YouTube channel.