How much food would one need to stock in such a situation?

That's a really great question. If it ever happens, will it last a month or 10 years to go back to normal?

that will reduce rancour and hate in society and devise better ways to dialogue rather than threats and rumours of war

Totally agree with this. Not sure why, but the last few years it seems like people have started to hate each other a little more, or maybe it's just that the people who hate others have become much louder, making it seem like the hatred has grown.