Board Thread:General Discussion/@comment-11242628-20151117211728/@comment-26487644-20151204011852

All aircraft and actually most of all military vehicles have whats called an IFF (Identify Friend or Foe) this allows allied radar to understand whether an oncoming vehicle is potentially hostile or not, especially given that on radar their usually isn't much telling you what make/model it is. If you are meaning aesthetically, well each nation roughly has a different colour scheme to their aircraft, and would most likely be enough of a give away. Many wars are fought like such even in our real world given most aircraft used by the unstable nations are usually either American made or Russian.