The "diplomacy" in Atlasia, existing as it does in a vacuum, has been in every respect a massive failure. At its best our foreign policy consisted of the SoEA writing fanfic about his heroic efforts on behalf of Middle East peace.
Yes, but having a second playable country is not the same as existing in a vacuum. Very few actually advocated that.
This is an interesting idea however, which was proposed or, at least, thrown around in the past. Obviously the details on what's happening outside of our two countries, implications of foreign policy between our two countries, and other future problems we don't currently foresee exist. While foreign policy, simulated by GM/SOEA hasn't really achieved any significant impact on the game, I question whether diplomacy between Mock Parliament and Atlasia is enough without outside, simulated, circumstances. I am however, completely on board with game-to-game diplomacy.