The "if" is "if the US claims they are real", as in, the military claims specifically the most plausible explanation of the evidence to them is that these objects are physical, solid objects, not illusions or artifacts.

Something real in this sense but unexplainable and not originating from humans does not mean space aliens. Just like it doesn't mean leprechauns or unicorns. Where'd "aliens" come from? The answer "I don't know, but we can rule out humans" is an insane possibility, but is one which seems both increasingly likely to be the truth and also much less insane than "it's aliens."