Re: Earth orbit..
"And for the moment, the enemy isn't anywhere up there."
Well if you are up there then the enemy won't get there first. You don't want to wait until the enemy is up or is about to be up there.
The way you win wars is to stop the enemy from being effective in waging war. E.g. Cut supply lines, cut communication, distract and separate the enemies forces, etc.
Satellites are a miltary asset that an enemy will want disrupt- if it can.