The war in Iraq has transformed the private security industry. Trends under way before the war started in March 2003, which saw the private sector take an increasing role in providing defence services that were once the unique remit of governments, have accelerated beyond anyone’s expectation.

Since the war began, the industry “has been on steroids”, says Peter Singer, an expert on the phenomenon at the Brookings Institution in Washington. The industry’s rapid growth has been controversial. Many on the left have an ideological aversion to “mercenaries” and the idea of profiting from war and insecurity, one commentator describing it as “disaster capitalism”.