IMHO, we don't need any of the military powers at all - at least not like it is in the current state with east vs. west. There is nothing like that on a globe. For America, Russia is west
However, we have the UN - an institution that includes almost all the countries on this globe. Acts against any of the countries must be dealt with there. This institution needs an army - consisting of all partial armies of the member states. Disputes between countries must be settled before this institution. And if one country acts militarily against another, then it must reckon with the consequences that this institution enacts. If necessary, this would also be military actions, if the diplomatic means are not sufficient.
It is clear that this will not solve the conflicts of this world, but it enables other nations to act and intervene in the name of this globe. Who wants to take revenge, takes revenge on the community of this globe.
I can't understand this ideology about this is my country and this is your country. Borders exist only because people draw them or have drawn them. Nature has no drawn land borders, which then also divides peoples into West and East and North and South. If mankind does not manage to overcome this hurdle, then we will probably exterminate ourselves soon.