1) Political agreements between all countrys. But never going to happen.
2) Flawless democracy without any corruption and with an ewen system so both the state/country and the people can reach to an agreement without making a 1 part more supreme than the other part from the start.
3) Bush stepping away from the President post.
4) Creating a good organisation for funds to poor countrys like Africa, and make sure that the money would be spent ewenly and correct. Again, not going to happen (to much corruption)
5) And probably the most important factor, that almost the reason to every problem. MANKIND NEEDS TO CONTROL GREEDYNESS.