Iraq War 2003: Since the 1991 Persian Gulf War, the U.S. and UK had been engaged in low-level attacks on Iraqi air defenses which targeted them while enforcing Iraqi no-fly zones. These zones, and the attacks to enforce them, were described as illegal by the former UN Secretary General, Boutros Boutros-Ghali and the then French foreign minister, Hubert Vedrine. Other countries, notably Russia and China, also condemned the zones as a violation of Iraqi sovereignty. In mid-2002, the U.S. began more carefully selecting targets in the southern part of the country to disrupt the military command structure in Iraq. A change in enforcement tactics was acknowledged at the time, but it was not made public that this was part of a plan known as Operation Southern Focus.

The amount of ordnance dropped on Iraqi positions by Coalition aircraft in 2001 and 2002 was less than in 1999 and 2000 which was during the Clinton administration. This information has been used to attempt to refute the theory that the Bush administration had already decided to go to war against Iraq before coming to office and that the bombing during 2001 and 2002 was laying the groundwork for the eventual invasion in 2003. However, information obtained by the UK Liberal Democrats showed that the UK dropped twice as many bombs on Iraq in the second half of 2002 as they did during the whole of 2001. The tonnage of UK bombs dropped increased from 0 in March 2002 and 0.3 in April 2002 to between 7 and 14 tons per month in May–August, reaching a pre-war peak of 54.6 tons in September – before Congress' October 11 authorization of the invasion.

The September 5 attacks included a 100+ aircraft attack on the main air defense site in western Iraq. According to an editorial in New Statesman this was "Located at the furthest extreme of the southern no-fly zone, far away from the areas that needed to be patrolled to prevent attacks on the Shias, it was destroyed not because it was a threat to the patrols, but to allow allied special forces operating from Jordan to enter Iraq undetected."

Tommy Franks, who commanded the invasion of Iraq, has since admitted that the bombing was designed to “degrade” Iraqi air defences in the same way as the air attacks that began the 1991 Gulf War. These "spikes of activity" were, in the words of then British Defence Secretary, Geoff Hoon, designed to 'put pressure on the Iraqi regime' or, as The Times reported, to "provoke Saddam Hussein into giving the allies an excuse for war". In this respect, as provocations designed to start a war, leaked British Foreign Office legal advice concluded that such attacks were illegal under international law.

Another attempt at provoking the war was mentioned in a leaked memo from a meeting between George W. Bush and Tony Blair on January 31, 2003 at which Bush allegedly told Blair that "The US was thinking of flying U2 reconnaissance aircraft with fighter cover over Iraq, painted in UN colours. If Saddam fired on them, he would be in breach." The Nuremberg Trials concluded that premeditated attacks on sovereign countries is aggression, the ultimate war crime.