One obvious way to prevent invasion is for the Nations to agree on set boarders and agree that the invasion of those borders would be dealt with be all the nations arising to protect against that invasion.
As part of this, weapons of mass destruction will not needed and will be eliminated from...
That is the discussion.
How can we end war?
It seems easy, let's try peace for a while and if peace does not work we could aways go back to war.
I see it will need to be initiated by a world wide effort, that will set specific goals to prevent war.
What about the Goals, what would they need...
God is One
Mankind is One
I see the entire structure of creation shows a cohesive bond is necessary for growth, including the human mindset.
Thus diversity does not negate our essential oneness.
This is the link the following quote is from.
What Would Happen If Everyone Truly Believed...
I stumbled on this and found it interesting.
https://www.history.com/news/when-america-despised-the-irish-the-19th-centurys-refugee-crisis
At one time, the Irish were the refugee crises in the U.S. I guess history does repeat itself.