From Conflict of Nations Wiki

Game Specific Messages

You can engage in diplomacy with other players in your current game through the Messages & Trades tab under the Diplomacy Panel.

  • Initiate diplomatic negotiations. You can offer another player a specific diplomatic relation in exchange for the same, or another. The other player will be notified about your offer and can accept or decline.
  • Be careful! Other players can hack your inbox and gain access to snippets of conversations by collecting intelligence.

If the sending/reply box is missing, try zooming out of the browser window.