Standard game play to not bust peoples shit in the hope they will return the favour. If they attack you where it hurts rather than card swap/hit non core regions then you go after them, otherwise you leave them alone whilst they leave you alone. Three player games are always a bitch fight anyway, and are suited to mouthy little tossers that like to accuse others of suicide, secret diplomacy, stupidity etc, trying to use the chat box to play the other two players off against each other, so the verbal fighter can walk the board. Waste of time playing 3player games really. The points don't add up, you have almost the same odds of winning a 5player game on a map you know, you gain more points for winning, and the same for losing, so why waste your time with a 3player. Sorry off on a tangent again.
Doesn't look like secret diplomacy, but thats just my unedumakated tinking.