Alienating Allies

I've now heard numerous times that because of our actions over the past couple of years, in particular the Iraq war, we are alienating our allies. Although "alienating American allies" allows a lot of alliteration, I'm not exactly sure what it means. I've asked people a couple of times now to give me more details but have gotten absolutely no response. It's apparently because they think that I'm such a dunderhead for not being able to see the obvious that they don't want to waste their time explaining it to me. So I'm hoping someone here will humor me and provide an explanation. In particular, I'd like to know who exactly are these allies to which they are referring and what is the cost to us (i.e. what's the downside) of said alienation?