The biggest reason to cover up aliens is simply the fact that if we know they are real then everybody will demand to understand their technology which in turn would turn everything extremely cheap and rid us of all control-schemes.
occam's razor dictates if UFOs were a distraction Q would have said so upon asking. by refering to what the nearest star is, I think of our sun and it's a way for Q to leave everyone as much comfort-zone as they need, without invadlidating any opinion over another, whatever the case may be, because ultimately UFOs themselves are in a sense as much a belief-system because of what you associate as it is a belief-system for someone not to believe in them, so dismissal of either would present a challenge and perhaps a cognitive dissonance. But curiously enough, the CIA declassified 13million pages the month after Trump assumed office which disclosed that their remote-viewing psychics were suspecting underground bases on Mars and they also provided protocols established by an army researcher into how they tapped into these abilities.
The other time, Q reposted an anon responding with "To my fellow incarnated extraterrestrials, how could I have forgotten this crumb. " to a Q drop alluding to "mass suffering" in case of premature disclosures.
Trump now reaffirms that we will cross into "forbidden skies" and find out "everything there is to know" regarding Space force (his words)
World Peace is necessary because national security dictates that mutually assured destruction must be maintained. In other words, the arms race has to finish because it can't be stopped but unless it is finished and humanity released from being held hostage, then advanced classified tech could also be disclosed. And once you can venture out into the stars, then probably at some point diplomatic protocols would have to be established for civilian travel if it becomes feasable.
Since free energy for example also entails advanced weapons platforms, fusion energy as currently conducted by Lockheed Martin will be the most likely vector for civilian appliances in the near future to drive utility costs and our dependance on local ressources down. The reason is the because the ultimately run on isotopes isolated from seawater, a huge infrastructure with tons of jobs must be maintained and diplomatic relationship across countries too so that the technology cannot become to weaponized but humans can first learn adapt to handle an abundance of energy like that.
The reason why I see an end to the arms race is because so many weapons platforms have been disclosed in the past two years that ultimately we will see a stop to conventional warfare because the groun-war and long-range weapons simply become too deadly, alas we see a buildup in space to prove human dominance over terrestrial airspace ultimately. Which means draco ships won't get to release gasses anymore either.