Blair's addicted to power and wealth. He already had the top job in the UK, but the UK's a small country these days. When he went to the US he was dazzled by the real power and wealth that lies there. He wanted to be best buddies with Bush, because Blair is always interested in being best buddies with the rich and powerful. THAT's why Britain invaded Iraq.
from the article: MI figures out what went wrong in Lavon affair - 55 years later