Not saying we won't win if it comes to a fight, far from it. Just saying that maybe a little more cation should be used when dismissing any potential threats credibility to threaten us.
Thing is, you're going "We should be more cautious because others may challenge us" to
far future plans. Naturally if the situation changes people are going to change the plan but currently we're the only ones in space, we're rapidly expanding our space capability and techs, rapidly expanding allies, and no one is looking to pick a fight with us yet.
If say, France, invests heavily in space capabilities starting next turn things may change, but from other nations' current interests and states it seems likely we're the only ones going for up as opposed to everyone else's around trying to gain more clay on Terra.
"Everyone may unite against you deciding to do something you haven't yet declared IC you'll do, with technologies they haven't researched since they have no idea that you're even taking this path that enables this thing you plan to do."
Also I believe part of this war is to help reinforce that yes we're strong naval and air wise both to ourselves and to other nations around, making them less likely to poke what was the world's greatest military force that they likely would believe had focused on being so again..
I mean, we had trouble getting intelligence on other countries until we actively started sending merchant ships out and even that's limited. Could you imagine an America that doesn't immediately focus on becoming top dog military wise again after an
alien invasion? Other nations got limited actions like us after all.
Nobody's expecting us to have the holes we left to focus on industry, research and quality of life. Which we
are sealing! Slowly but surely.