To say that the matter of the legality of the armed conflict against Iraq in 2003 was divisive is an understatement. The primary justification given by the UK government for the lawful nature of the Iraq war (2003) was an implied mandate from the Security Council. The implied mandate was said to be derived from a combination of Security Council Resolutions 678 and 1441. Many international lawyers remain unconvinced that such a mandate can be inferred from those resolutions. There is agreement among both supporters and opponents of the war in Iraq that Saddam Hussein’s regime had an appalling human rights record. This was known to the coalition governments; indeed, Tony Blair expressly made the "moral case" for war on the basis of Hussein’s human rights violations. The legal justifications offered for the conflict by the UK government, however, did not refer to humanitarian intervention. This paper investigates whether it is possible that, despite the fact that the justification was not raised by the UK, it can provide a defence to any claims that the UK acted unlawfully, or that individuals committed an international crime, by initiating the attack on Iraq.