The force doesn't work on extra galactic life such as the Yuzan Vong. The only way to use the force against them would be to pick up a rock and hit them with it force push/pull do nothing directly even battle meditation to find out where the enemy will strike and in what numbers doesn't work.

[i]The Force wouldn't be enough to protect them from the star roads. Without the Halos, there's no defense. [/i]