In the first story in the issue, Gustav Borlin, the dictator of a "neutral but unfriendly" unnamed nation, is going to give us a new definiton of the term "neutral":
The 2nd story in the issue begins:
And our 3rd story...
Mysterious aliens, it seems, are using meteor swarms to knock our nuclear missiles out of orbit so Earth destroys itself...
Anyway, Captain Atom destroys the (invisible!) aliens with one blast. The end.
Yes, all 3 of the stories were in one issue--Space Adventures #38 (1961), as reprinted in Space Adventures #10 (1978). No author is known, even though the art was all by Ditko, so I don't know if one gent was responsible for all three, or if it was a coincidence that all 3 tales are essentially exactly the same.
It is interesting to see that, at a time when super-hero comics were ignoring the contemporary geopolitical situation except in the most superficial ways, that Charlton was willing to wallow in the existential dread of nuclear extinction.
Still, you've got a superhero who can do virtually anything, and all you use him for is (repeatedly) running into orbit to shoot down nuclear missiles? Boring...
