Conflict resolution usually takes form of diplomacy, negotiation which lead to peacekeeping, peacemaking and peace-building. It depends on the conflict of how long does this process of resolution will take. Of course other kind of action can lead to conflict resolution. Since people is the main focus here, other approaches such as art can make a big contribution to a resolution.
Art has always been a part of every day life. People can get values and ideas trough art and it's in a way that people enjoy. There are a lot of visual art representing sorrow and sadness regarding to an actual conflict. Not only to make people understand, this art also can be a way of seeking help. To truly understand the condition of people and what is the conflict about.
Take a simple example. Students who are in a depression tends to pour their hearts into words or in this case, visual art, like short movies, paintings and drawings rather to directly confess them. Because trough art, other students or teacher can understand then approach that one student. Students who do art can get help from people that actually care about them trough their arts.
In this context, visual art maybe doesn't have a direct role in conflict resolution. But, art can move people by values and ideas poured in it. In my opinion, art does help conflict resolution. Aside from its nature that is peaceful and calming, people can freely interpret art so that ideas and values are developing.
You have posed a question that is at the heart of much of my artistic activity and also my peace work. Sometimes I have to call attention to some glaring omissions in vocal tones that are not simply quiet and dove-like, but mostly I do try to keep it peaceful.
Art speaks to the heart and factual essays speak more to the mind. That is, art can reach places in people that simply arguing and citing facts cannot.
We can actually do much with street theatre. This kind of art is direct and emotional. Street theatre goes to the heart of a case and reaches more people than art in a gallery or museum (unless the top artists who are world famous.) Consider art that is most accessible. That is the way--a way--to get the values out that you are seeking to communicate.
A problem in peace groups is that they stage many events speaking to those who decide to come because they already agree. Pre-selection of the already-motivated audience means slow merely a slow growth of communicating the ideas. Street theatre is just out there and whoever comes by hears and sees it without "playing it safe" and, as we say here in the US, preaching to the choir.
This being out there and accessible is most important in conflict resolution. It is important to set up events where more than one's own side attend.
Liebmann, Marian (ed.) (1996) "Arts Approaches to Conflict".
Arts Approaches to Conflict explores how various arts approaches can both raise our understanding of conflict and lead to its constructive resolution. Practitioners and experts from a wide range of art forms examine their own fields as approaches to conflict. It is fascinating and eye-opening reading for students and practitioners.
Art therapy to counseling is an interesting concept, and should be explored as part of evidence based treatment. As radical a concept as it sounds, it should not be, "One size fit all" approach, rather used in combination of other counseling treatment, until it full benefit is realized. Great idea, worth exploring.