Saudi Arabia has overtaken the UK to have the fourth largest defence budget in the world, with an annual outlay of $59.6bn in 2013, according to newly published estimates from the International Institute for Strategic Studies (IISS), a London-based think tank. Riyadh’s defence spending has been ramped up massively over recent years. From just over SR69bn ($18.4bn) in 2002, the budget for defence and security had climbed to SR251bn by 2013, according to the Saudi Arabian Monetary Agency (Sama – the central bank), whose figures differ slightly from the IISS estimates, and show a defence budget that is even higher (see graphic).