Driving the conflict [The Island]

I was out mowing the yard. It was dry enough, finally, to allow me to get to the back corner of the lot.

Mowing is one of those activities I am able to do and ponder other topics. Today's topic was conflict. In The Island I want a conflict resolution that pits the characters against one another in two-sided situations where the island itself applies leverage to one or the other side. I don't really want GM versus player conflicts but I want the players to feel as though the GM is unbalancing things one way or the other.

These are the points I was mulling over.

1. A scene is defined by the GM. The players can suggest things but the GM has final say in framing the situation.
2. A conflict is a two-sided end to a scene. The players pick sides roll against one another.
3. The GM has a pool of dice to push the conflict one way or the other.
4. The longer a conflict goes on the more out of control it needs to feel for the players.
   

At least those are my initial thoughts. I'm sure they will develop in time.