[dojango]

There's nothing inherently wrong with participating in a 3 v. 1. I seem to recall once being attacked by Atlantis, Marignon and Tien Chi while playing Patala in one game...

The main disadvantage, of course, is that a late-comer nation will usually receive the least amount of the spoils, and is the most likely to lose his gains to the other two once the war is over. In the situation I recall, Tien Chi and Atlantis then ganged up on Marignon, depriving him of his share of Patala. So it was probably a mistake for Marignon to join in the coalition, but he wouldn't have known that betrayal was coming going into the war (especially because the logical move would have been for Tien Chi and Marignon to gang up on Atlantis, who was by far and away the strongest power in that game).

The general rule of thumb is that you don't want to help strengthen someone who's stronger than you. Without knowing the details in this situation, I can't tell if anyone is making that cardinal mistake, but keep in mind that it is often better to let your strongest neighbor get bogged down in a long war than it is to help him to an easy victory.