Rules of Statesmanship and Warfare:

1. Know your friends from your enemies
2. Know which of your enemies are potential friends, and pursue all avenues for peace.
3. Know which of your enemies are intractable enemies, and wage war against them mercilessly.
4. It matters little what people say, it's what they do that counts.

sometimes attributed to Menachem Begin, but I can find no reputable source to prove that. Honestly, I've repeated it often enough that I sometimes think I wrote it.

You can make peace with three groups of people:

1. People you defeat.
2. People who have defeated you.
3. People who are potential friends.

Conflicts resolve when both parties expect the same outcome. This is true on both a personal and state level.

Third and Lastly: