I used this Strategy in one of my first games (maybe not what you are talking about). Won the game, other player called it Cheap and Coward.
Four player game. Conquered South America first turn. Had Placed one unit in Havana (making it 4) same first turn.
Only two units on my border (Bogata) Thought I would take a chance and wear the guy down next to my Border (from havana, with four units). Mission accomplished. Proceeded to Wear down next terit in order to prevent attack from him as well.
Brought him down to one unit...went on to next terit, worked out well. Ended up wearing every Terit down to one unit while I kept my four units.
Attacked Mexico city lost one unit (something that always happens when I attack a 4 to 1)
Ended up with 2 units on two terit Protecting my Border.
Weakened three terits and conquered one.
A move like that would not put me at risk and there was nothing to lose and so much to gain.
There are times when you should play the dice...not always about playing the odds.
Having a feel for the game.
Play for the best hand possible.
'Poker' If you have two pair out of five cards what you going to do?
Keep the two pair and ditch one card and hope for a full house (three of a kind followed by a pair)?
Or are you going to ditch three cards in the hopes of getting three of a kind?
Go for the full house! Always go for the best hand possible.
Sometimes it is better to reduce enemy terit oppose to conquer said terit.
Most players do not even know who or how there terit got reduced (in a four player game). Eliminating any retaliation.
Also good when you have a truce with a player in a multi player game. Reduce but no conquer terit as to leave no evidence (game log)
Depending on what kind of truce you have. Non-aggression pact would be dishonorable to do such a thing. That is why I try to make Buffer zone treaty oppose to non-aggression pact. Buffer zone prevents you from taking control region or terit...nothing wrong with Attacking it (wearing it down).