So for the last day or two, people have been making fun of the idea of a Space Force. I even got in on it. But in all seriousness, do we need a Space Force? As far as I know, no.
The job of this theoretical Space Force is currently done by the Air Force. This includes handling the GPS satellites, military communication satellites, and the security making sure they aren't hacked by foreign powers. To the best of my knowledge, there hasn't been any major screw up showing the Air Force is so incompetent that these duties need to be taken over by new management.
A case could be made that we might need some Space Force in the future, and it's easier to form it now. The idea that it's easier to transplant a sapling than a full grown tree. But what tasks will this Space Force be needed to do in the future? As far as I can see, what the Air Force is currently doing ... only more. Is that enough justification to make a whole new military branch?
Times are changing. We are inching towards the era of space tourism. At first with just suborbital hops, but soon tourists will be going to space hotels. It's possible that thirty years from now some terrorist will take the tourists in a hotel hostage and someone will need to rescue them, like Executive Decision ... in Space! But you wouldn't need an entire Space Force for that, just ... Seal Team Infinity? Although it might be hard to find an entire Seal Team with everyone named Buzz.
If we do make this Space Force, what would the Air Force do? I mean, the WWII visual of hundreds of bombers with hundreds of fighters escorting them deep into enemy territory to carpet bomb an industrial district doesn't happen anymore. We're getting to the point where we can have hundreds of drones waiting for a bunch of cruise missiles (fired from ships, which used to shoot at other ships with guns) to take out a country's air defense system before going in and bombing other targets pinpointed by special forces units on the ground. Getting the military working together as a cohesive whole is the way forward. Making a new branch of the military, would probably just make that more difficult.
So, do we have a need for a Space Force? No. Would a Space Force make America safer? No, and the shakeup of the current system might open a window of vulnerability. A Space Force sounds cool, but that's probably it.