not sure if you're still thinking through issue with friend, but here's my $.02.
You talk about them being defensive and how that makes you feel, but defensiveness isn't about you, it's about them. And it means they won't listen no matter what you say, until they're ready to listen. Most times it takes some kind of trigger of awareness for them, something they encounter in another context or a small, digestible thing you say, that opens them up to hear the rest of it.
Guess I'm saying, don't roll in with the 101st airborne division of reason, but think about how to make smaller steps towards the bigger discussion making sure there are plenty of opportunities to judge whether they are listening or shutting down. Sometimes it takes a while. And it also gives you the chance to hear them as well - something we often don't do when we're absolutely sure of our own opinions.
