There is only one way the US didn't know it was Ukraine.
If you were monitoring communications, you'd be able to pick up a lot of stuff.
For example, let's say you're monitoring group and they're celebrating this. That's one indication. However, if the group is all talking about, who do you think did this? What do you think happened? And they're genuinely confused? That's an indication of something else.
People doing signals intelligence talk about this type of "chatter."
If you were monitoring communications, you'd be able to pick up a lot of stuff.
For example, let's say you're monitoring group and they're celebrating this. That's one indication. However, if the group is all talking about, who do you think did this? What do you think happened? And they're genuinely confused? That's an indication of something else.
People doing signals intelligence talk about this type of "chatter."
But the C Eye Assholes would know how SpaceForce would be able to monitor so they took this operation completely offline.
Space Force does not do that.
https://www.govinfo.gov/content/pkg/GPO-INTELLIGENCE/html/int023.html