Your opponent isn't gonna sit around after using his duel strike. He'll smash into your sorry army that's been beat up by the SCOPs. Once your turn rolls around, your air force is useless, if not mostly screwed. They've been beat up, have lost half their fuel, and have double fuel use for a few turns. What can make it back for refueling will be out of the fight for a bit. Meatwalls can easily be broken with this power.
An Andy and Jess Duel Strike would be the best way to minimize damage to what's left of your army. Of course, it can't save your dead units. And it won't fully heal the really beat up ones.
Now, if the enemy has some recons prepared, they can start the duel strike with Drake as soon as its their turn. If they don't, they may not want to start it until after Drake moves, due to fog.
In any case, this duel strike is very powerful. In addition to the two turns duel strikes provide, you get to do 4 damage to all enemy units, get rid of half the fuel of all enemy units, and increase their fuel use for a few turns.
Edit: Your navy will take a hit too. Mostly your subs.