If and it’s the biggest IF in human history, the government has definitive proof of alien life and has retrieved alien spacecraft, with pictures, videos, etc.
It would be biggest announcement in human history; it would totally rewrite physics as we know it that intelligent has found a way to overcome the space time continuum.
Some people will never accept the proof, the way to get the most people to accept that we are not alone is a bipartisan approach of all former living Presidents to all say the same thing.
Who’s to say it has to come from off of Earth?
Some pretty paradigm-blowing science was done in the 20th century - and that’s just what we know about.
I will accept physical evidence I can see, touch, and examine in public. Nothing less.
All we have are alleged witness accounts, claims of alien bodies, claims of alien spacecraft wreckage, claims of alien reverse engineering, claims of alien technology, claims of alien implants, claims of alien hybrid babies, blurry photos, and short and shaky videos people tell me, without evidence, are alien spacecraft.
Show me physical proof I can see, touch, and examine and I will accept aliens are real and have visited Earth.
Obama already said it