What began as a US-Israeli assault on Iran is rapidly evolving into a conflict with the potential to spread far beyond the Middle East.

Iranian missiles and drones have already struck or reached Turkey and Azerbaijan, while European powers are rushing additional warships, fighter jets and air defences to the eastern Mediterranean and Gulf to contain the fallout.

Analysts warn the longer the war continues, the greater the risk that long-simmering regional fault lines – from Kurdish militancy to...