When the US invaded Iraq in March 2003, the Bush administration estimated that it would cost $50-60bn to overthrow Saddam Hussein and establish a functioning government. This estimate was catastrophically wrong: the war in Iraq has cost $823.2bn between 2003 and 2011. Some estimates suggesting that it may eventually cost as much as $3.7tn when factoring in the long-term costs of caring for the wounded and the families of those killed.

The most striking fact about the cost of the war in Iraq has been the extent to which it has been kept "off the books" of the government's ledgers and hidden from the American people. This was done by design. A fundamental assumption of the Bush administration's approach to the war was that it was only politically sustainable if it was portrayed as near-costless to the American public and to key constituencies in Washington.