The Nordic archetype enters through George Adamski's claimed 1952 meeting with 'Orthon' near Desert Center, California, detailed in Flying Saucers Have Landed (1953, with Desmond Leslie), and peaks with Frank Stranges's Stranger at the Pentagon (1967), the Valiant Thor story. The era's contactees, Adamski, George Van Tassel, Truman Bethurum, uniformly reported beautiful humanlike visitors with anti-nuclear messages. Declassified FBI files on Adamski document the bureau's assessment of him as a fraud; his photos were debunked as a chicken-brooder lid in his lifetime.
The Nordics never left: they evolved into Pleiadian channeling, the Ashtar Command (channeled from 1952 by Van Tassel), and modern 'galactic federation' content, the benevolent elder race that wants to help but is bound by non-interference, a doctrine conveniently explaining their absence.
The analytical point documented by folklorists: contactee aliens track the host culture's self-image. 1950s America met anti-nuclear Scandinavian humanitarians; other eras met demons, fairies, and airship pilots (the 1896-97 wave's crewmen claimed Kansas addresses). The Nordics are the Cold War's mirror, which is data about the mirror, not the stars.
If the visitors always match the era's ideal, are they coming from space or from the mirror?