Replying to Separate Nations vs Unified World

I've been reading Asimov quite a lot lately and it got me thinking about the advantage and costs of a Unified vs Seperate World.

I think that it would be beneficial to be unified as a species, as we come closer to our carrying capacity cooperation might be the only thing that could save us. Asimov brings up an interesting point and talks about how it is foolish for a species that is growing larger to cooperate less, because the success of that species relies on a close to equal succes of its individuals.

But would it be worth the cost of freedoms? Is the only way to reach a unified world through war? Obviously a Unified World is more of an ideal than reality, but I'm interested to see opinions especially with the shakiness of are current world.

Discuss