Regarding AI, the answer is actually pretty simple.
Just don't do it.
Unless you have some serious RL issues and you absolutely cannot find a sub, of course.
Regarding nations 1 and 2: if you're absolutely sure you cannot win no matter what you do, AND have no agreements with them, AND have no other reason to support particular side, use a 3-sided coin (help 1, help 2, turtle). Otherwise, do everything you can to win. Really simple
