What exactly is President Donald Trump trying to achieve in Iran, and how does it compare with past US interventions in the Middle East?Before the Iraq War, Secretary of State Colin Powell warned President George W. Bush about what became known as the “Pottery Barn rule”:“You are going to be the proud owner of 25 million people… You’ll own all their hopes, their aspirations, and problems. You’ll own it all…. The Pottery Barn rule, ‘You break it,…