[aortega]

Of course it will not stop all wars, but it will stop most oil-related wars. You still will have resource-related wars like cultivable land, and fresh water but with the space-revolution soon humanity will have plenty of land and water too.

[RockyMcNuts]

Well... if fusion energy is abundant, the price of oil will drop rather abruptly. A lot of people in a lot of places, where the population has been expanding, and there is a lot of religious extremism and political instability and modern weapons, will have to find a new way to feed themselves. And someone to blame if they can't. So I'm not that optimistic it will stop any wars.