Answer:
Great Britain
Step-by-step explanation:
In 2003, Iraq was invaded by the United States, but also three other countries. The three countries that got involved into this invasion were all members of the military organization NATO. Two countries from Europe got involve, Great Britain and Poland, and plus Australia. The official reason for the invasion was the alleged development and usage of bio-chemical weapons for mass destruction by Iraq. That turned out to not be the case, as the UN inspectors had full access on everything but didn't found anything, but the invasion took place anyway, with the real reasons most likely being economical because of the large oil and natural gas reserves of Iraq.