There are two main issues. The first is whether the British and US Governments exaggerated ("sexed up" in the words of one unnamed source) the basic intelligence on Iraq weapons in order to justify a war. The second is whether the intelligence was wrong in itself. There is another but subsidiary issue about a background paper from the UK Government listing Iraqi human rights violations. This was found to have been partly based on work by an American student.
pretext War On Terror war profiteering UK USA invasion Iraq human rights WMD