For people that want to learn about the U.S.'s overseas activities, that CCR site will pretty much answer anyone's questions about our foreign policy.
I'd like to add an item I found out about from Gore Vidal's book "Perpetual War For Perpetual Peace". In it, he lists over 200 military incursions since 1945 involving the United States; in most instances as the aggressors. His list came from The Federation of American Scientists. Here's a link to a list of U.S. military interventions from 1798-2001:
I say take a look at the list, if for no other reason than to fully appreciate the staggering amount of foreign conflict the U.S. has engaged in. Pay special attention to how many of these have occurred since 1990, in comparison to the past.