ICBM trajectories, reconnaissance satellites, even GPS satellites (that have become important for civillian uses). They're all in space, or... mostly in space.
There's a difference though. They're all related to fighting on Earth. That's because pretty much everything worth fighting over is on Earth.
The "science" you see in Star Trek is utter rubbish. The aliens are utter rubbish, the spaceships are utter rubbish, the weapons are utter rubbish, the planets are utter rubbish... may I go on?
When you see Star Trek or Star Wars or anything similar, try to think of it as technologically themed magic. Because that's really what this sort of soft science fiction is... a "science-fiction" themed fantasy.
I do not wish for war to happen in space. I do not wish for war to happen
anywhere. But... when it does happen, it'll be because there is something there that is worth fighting over. Whatever that might be, it probably won't be a reason to fight in the next few centuries to come.
Interestingly enough, the Outer Space Treaty may prevent many reasons for war... for example, it means you can't claim land on an extraterrestrial body (and presumably can't claim mineral rights- or can you)? If resources on another planet are the common heritage of mankind, nobody can claim them for themselves... maybe it is a cause for concern when some paraiah cuts up a nice little resource-rich patch of the Lunar surface and blocks all others from entering it... until the UN calls for another one of those "no fly zones"...
It would require alot of reasorces to get an army that would fight in space and then if they are unable to be supported or resupplied from earth they would either surrender or die.
Nobody is talking about "an army in space". War and "launching armies into space to do battle in space for no real reason" are two different things.
Plus there is as of yet no practical way of attacking the surface from space.
Wrong. The capability to deorbit from orbit has existed, along with manned spaceflight, for 50 years.
Already by deorbiting something with precision from orbit (something that won't burn up too easily), you have a way of attacking the surface... precision targeting is not impossible, as it is done already by nuclear missiles.
See Rods From God and similar concepts. They are non-nuclear, hypervelocity weapons intended to be used on surface targets from orbit.