Then they'd retaliate in kind, and we'd get nowhere. It's certain they have that capability, or can develop it.
We stand to lose a lot more from a space war, right now, than anyone else. We (US/west) hold the lion's share of space commerce and orbital launch capacity. "Earth orbit is free and open for everyone" is more than Star Trek idealism—it's a precedent we've set that benefits us, especially.