Confusing advice and on-again-off-again airport closures are complicating the evacuation of hundreds of thousands of foreigners stranded in the conflict zone around the Persian Gulf.

A wide area of the Middle East is now considered too dangerous to fly, forcing some Asian-bound flights to burn more fuel diverting around the danger zone. Flight radar shows an oval-shaped area about 2,500 kilometres wide and 2,000 kilometres north-to-south, centred on Iran, almost devoid of civil aviation as the country endures bombardment by the U.S. and Israel.

The main hazards for civil aviation in the Gulf — affecting the airspace of more than a dozen countries — are not the hundreds of retaliatory ballistic missiles and drones that have been launched by Iran, although they certainly pose a risk.

The more dire threat is the heat-seeking air defences of countries swept into the conflict.

Flight radar shows civil aircraft taking a wide berth of the conflict zone, with more movement from relatively distant airports such…