The why is pretty obvious.....personel, equipment, logistics, intel, etc.
The who, is whoever is behind helping to put together this plan, split up between those folk. You think your joint U.S./USSR nuke deterrent is a freebie? Nukes don't grow on trees, and nuclear devices don't make themselves. Same principle, only fashioned around reality of using standard ordinance and manpower, and whatever else is necessary to enforce the peace, thru monitoring, intel, and these repercussions, if they become necessary