I don't think we have an imminent race war. Race is a funny one because you have religion mixed in, and there are intrinsic links to our battle to get equality for women, sexuality, gender issues etc. The tension is rising around all these subjects because we are becoming more enlightened as time rolls by. We are realising that equality for women is simply right. The equality for people of different sexuality is right. The equality for people regardless of race is right.
However those principles are slightly at odds with some of the religious teachings and/or how different religions has been practised for many years. So there is tension immediately. Also for sure the media is stoking some of these fires too, you'd have to look closely as to why that is...
Temperature is also rising because of fundamental differences between peoples. The world has become a smaller place so migration of peoples is more regular and doesn't happen en masse. If you look back throughout time the migration of people from one place to another has always caused tension. Previously it inevitably led to war. Very few people who migrated settled in their new land peacefully! Now you'd hope we would be able to take a bit more of an educated approach to this, but the reality is all countries are still very insular/nationalistic at their heart. Its different now as you don't get as many mass migrations like the past. We are having to wrestle with our desire to take enormous pride in where we from, and a desire to welcome all comers. Its not easy for people because when you take pride in where you are from, you do not easily allow another "outsider" to attach to your country. As a minimum you do not accept it without expecting some level of immersing themselves in the history. Also what is an acceptable approach to something in one country, is not in another. So people will trip and make mistakes, and people will get frustrated.
What I would say is there is a reason for significant hope in our younger generation. They may have **** taste in music but I look at my 10 year old and how she views the world. Their relationship with people of different religions, race, sexuality and sex is very different to the past. The problem is like every generation they are saddled with the past left by all that have come before them. The past influences our future and the past tells us that the migration of peoples and races is not altogether positive. Tension is inevitable.
Don't worry though the end game will see us dispense with religion, we'll probably all become one gender, and we'll all end up one race. Probably a light brown - yee hah for an ACS type as it dispenses with the need for fake tan.