Joe Biden says a mouthful
You want to talk about emboldening our enemies, 6 years of aggression without engagement has done more to embolden Iran and motivate them to become a real threat than anything else. It's a failed policy, it's time to freaking try another tack.
NOT, as McCain would like us to believe, with the goal of making Iran our bestest buddy, or of appeasing them, or of letting them have their way. With the goal of actually getting a handle on the situation, getting as much information as we possibly can on ALL of the factors involved. Keep your friends close and your enemies closer. Not talking to them does nothing but make it harder to really know what's going on. And that's reflected in the faulty intelligence that continues to pile up and (mis)guide our foreign policy decisions.
Not that talks will necessarily fix the intelligence, but it will provide another data point to refine what we know.