ignoring the ramifications for various nations....

[phyzik]

If it where possible to just pull out all troops from all nations back to their homeland, knowing that your nation would be safe (absolutely no economic, environmental or retaliation effects at all), and let these small nations duke it out, would you do it?

[Nbadan]

Remember that WW1 AND WW2 started as wars between what were then 'small nations'...there was no NATO or unified military, so nations formed their own treaties that obliged them to fight as one if one country was attacked...