We already have that on a smaller scale most conflicts have paid mercenaries involved people with little scruples or morals prepared to sign up to the highest bidder.
The problem with the army that you suggest is who would have ultimate control of that army as of the way of the world politics would control it with the major powers having the big say and each of those have very different agendas so we are just back to square one .
It would come down to financing it and ultimately the countries that could afford to support it are the countries already with most influence
IDF2 (16-08-21)
A difficult enough thing to do. You cant deal with the likes of the Taliban peacefully. The chances of the US and their allies moving against the Taliban are very high. You'll have a huge loss of life. As long as the middle East exists you'll have US interference in some form or another.
Westside