Apologies for the (ahem) slight delay in responding to your earnest enquiry regarding the reason for your country's warmongering and regime-changing escapades around the world. With respect to Iraq specifically, maybe this will help, and simultaneously entertain you to boot. So go make yourself a nice cup of your favourite brew, put your feet up, relax, and enjoy:
I should add, in the interests of fairness and balance, that my own country (the UK) is not entirely blameless in such matters either, though I'm not sure it can so much as hold a candle to the USA's rap sheet. And you don't even have an empire, a concept which (ostensibly) uncle SAM spurns with disdain. So you replaced it with 'sphere of influence' instead. Hmm......pull the other one.