Is world peace possible?

Earlier this week as a class we went through a simulation where we were divided into 6 groups that each represented a country. We didn't know in the beginning that if we went to war, we failed the simulation. From the beginning of the simulation when we were told that our goal was security, my group thought of an idea for an alliance between all the countries. I am sure that we weren't the only ones. However, none of us would stand up before the class and propose this. So then we just carried on with the simulation trying to save ourselves because we were the weakest country. We made allies with anyone we could because we needed all the allies that we could get since we were practically powerless without them. We were eventually part of this huge alliance with the rest of the countries but one. We decided to attack the country that stood out because it wasn't a part of the alliance. This is when we failed. We couldn't even have classroom peace in this simulation, yet we probably could've accomplished classroom peace if one of us had of spoken in the beginning of the simulation. Looking back on it, it seems like it could've been so easy, but we didn't do it. So if you take this simulation and apply it to the real world, could world peace be this simple? Just someone needing to stand up before the world and make the proposition. I personally think it is impossible because there much more than 6 countries in the world, with far more than 6 people in each country. And with more people come more ideas and more conspiracies. But what do you think?