Horses to nukes in 40 years is very suspect, indeed.
How many scientific journal articles from the late 1800s to the early 1900s have you ever read?
Have you ever studied about how Millikan measured the charge on the electron?
Have you ever read Einstein’s paper about how Brownian motion is used to estimate the size of molecules?
All that work and other efforts formed the basis for our modern quantum mechanical knowledge. They used very crude methods with much mathematical pencil and paper work to make amazing discoveries.
Admirable? Of course!
Alien? I think not.
There is human hard work and intelligence used to build and discover all of our science.
And not much since….I think they took one look at us and left.
The scientific discoveries and technological innovations that made nukes possible are abundantly documented. The best case for help from aliens is to the effect that technology from downed UFOs was helpful, with some suspicion that in recent decades, UFOs were deliberately downed or left available for human access.