The Mongols were the last force to make any progress through the territory in 1219–21 and since then attackers have ground themselves into dust trying to make headway across the mountains. By the time of the Second Gulf War in 2003 even the USA, the greatest fighting force the world has seen, thought better than to take a right turn once it had entered Iraq from the south, knowing that even with its superior firepower Iran was not a country to invade. In fact, the US military had a catchphrase at the time: ‘We do deserts, not mountains.’
