If our aim is to prepare for war, then we need to focus more on space warfare than we currently are. Whether or not we ultimately need a "Space Force," or whether we simply need to ensure that our Air Force is focused enough on space, is up for debate. But the idea is taken somewhat seriously, yes.
Why Would We Need a U.S. Space Force, Anyway?
We currently have a wide variety of space-related military efforts, but they are spread out over a multitude of different departments of the military, making them less efficient and focused:
Disparate space-related efforts are scattered across the Army, Air
Force, and Navy, not to mention intelligence officers, National
Reconnaissance Office and Space and Missile Systems Center. Doug Loverro, a former DoD Deputy Assistant Secretary of Defense for Space Policy, noted that fighting in space is different than fighting anywhere else, in the same way that the Navy prepares for unique combat at sea. “We lack that focus for space, one of our five main warfighting domains,” he said.
If war were to break out, we would have a significant problem communicating with our troops:
These threats, Loverro said, are already here. If a war broke out in the Pacific, commanders would have a hard time communicating with troops. “We have a SATCOM jamming threat today,” Loverro told Congress. “We have nothing on books until 2027 to solve that problem.”
Other countries are prepared to attack our satellite infrastructure if it comes to war:
Gen.Kehler said the stakes are high because the loss of critical assets in space could prove decisive in a future battle. Potential enemies know this and have been investing in weapons on the ground or in space to take out or jam satellites. “Time is not on our side,” he said.
There is some disagreement as to whether we actually NEED a space force, rather than a new focus, new ways of thinking, and better organization:
Loverro ... concedes a new service may not be needed. “We don’t need to move it from the USAF to create the space smart-force we need,” he said.
I can say that there are many Americans who are of the opinion that asking a current branch of the U.S. military to promote "new focus, new ways of thinking, and better organization" would be a lot to ask of such a large, entrenched bureaucracy.