Many people express pain when they believe Nonviolent Communication should enable lasting connection between any two people - I would say there is absolutely zero hope of this* - but NVC can help two people get to unity quicker, for example, to get to agreement that they aren't going to be in regular contact. Since I reached this understanding I have had much less stress and conflict in my life, especially with NVC people!
* because of personality clashes, circumstances, preferences, differences in style, cultural differences, different priorities in NVC learning, different life priorities, and above all different needs in relation to communication/friendship at any one time.
Marshall Rosenberg has pointed out that people often do terrible things because they want someone toknow how they feel. There's a great example of this in the newest Star Trek movie. The bad guy Nero is very upset because his home planet was destroyed. He blames Spock and in order to get the empathy he needs he decides he will in turn destroy Spock's home planet. I can't find any clips that show Nero demonstrating this need for empathy, but here's the actor who plays him: http://www.youtube.com/watch?v=1y7ZrTlsbok Drawing by bglasgow, www.flickr.com, CC: attribution sharealike