Yea I guess I agree with you then, so here is the information:
Whenever a player types -ally player_color (color from red to brown)
the target player should get a messege that triggering player would like to become his ally, so if he types -accept or something like that then they become allied, not shared vision though, only allied.
Then there should be command -unally player_color this will without asking the target, tell both players that they are unallied now and offcourse. unally them
Last command will be -war player_color this will just tell the target player that triggering player has declared war on the him.
Hope it's understandable.