I just finished reading Turledove’s Noninterference last night.
It’s one of his earlier books – the first copyright is 1985. However, the setting of the book (a Human-led Federation sends out star ships to explore other planets, but the explorers have to be careful not to interfere in the natural developments there) is so close to Star Trek: The Next Generation (1987-94) that somebody must have inspired somebody else. The main difference seems to be whether the rule is called the “Prime Directive” or “Noninterference”.
Anyway, the plot of the book is more like a crime novel and not very Star Trek-y at all. The dialogues are dreadful in typical Turtledove fashion (every time a person says something, it’s explained afterwards what it means, as if he expects the reader to be completely stupid), but it’s actually quite readable.
However, one fundamental conflict in the book is between the Survey Service (also known as Starfleet in Star Trek), who think that it’s OK to observe all planets, and the Purists, who think that planets without space travel should be left well alone.
To me, that conflict sounds too academic to be realistic. There’s no economic incentive to choose between the two groups, and money normally tends to be a factor in human power struggles.
I would have thought a more realistic conflict would have been between Colonialists (mimicking 19th-century Europeans) and Observers, but that would of course have been an entirely different book.