Iran is entitled to attack enemy warships and stop enemy vessels, but it is not allowed to attack vessels from neutral countries or attack all commercial shipping indiscriminately, Klein said."Iran has threatened to attack all ships coming through the Strait of Hormuz, which is not consistent with the law of naval warfare."The strait is the only way in or out of the Persian Gulf, a key area for oil production in the world.About 20 to 25 per cent of the world's oil supply transits through it, alongside LNG, fertiliser and other goods.That's led to a significant knock-on effect for the global economy, Parker explains, partially through panic (and subsequent panic buying) and later, the real supply crunch — which takes longer to arrive."It will be felt," Parker says "Iran always attacks ships when it wants to make a political point."On Monday, two India-flagged tankers carrying liquefied petroleum gas sailed through the strait — a significant sign of movement.But analysts remained cautious."Iran is assessed highly likely still capable of damaging shipping transiting the Strait of Hormuz," British maritime security group Ambrey said.Beyond the security question, tankers that would normally run Gulf routes may have been reassigned to other charters and won't be immediately available.On when volumes may return to normal, Parker says: "It will not be immediately."For the latest from SBS News, download our app and subscribe to our newsletter.