The choice of future track gauges in Afghanistan presents several difficulties. Afghanistan is the cross-roads of Asia, surrounded by three different kinds of gauge, and yet is almost completely without railways. Until the 21st century, there were less than 25 kilometres of railway inside the country, all of which is built to 1,520 mm (4 ft 11+27⁄32 in) Russian gauge. For strategic reasons, past Afghan governments preferred to discourage the construction of railways which could aid foreign interference in Afghanistan by Britain or Russia.