SOLVED. SciFi: Man frees Earth from Alien oppressors. Read around 1976-1986. Spoilers ahead. [s]

[Michael]

Aliens have taken over/oppressed the Earth. In the future (2000s?), the hero, working with a sympathetic alien politician, maneuvers to get Earth's freedom. He ends up having to betray his best friend (I think the friend was executed as a result).

I remember that we got this as a cheap paperback (Ace? Avon?) from K-Mart when I was a boy (probably 1976-1986); it was about 4x6 and 1/2" thick. I think it may have been a cheap reprint of an older book.

Cover had a green circle motif behind a human, the rest was white. I think the tagline was "TO SAVE THE EARTH HE HAD TO BETRAY HIS BEST FRIEND"

[Andy]

How about "The Dark Planet" by J Holly Hunter The Dark Planet - the cover of which says "TO SAVE THE EARTH HE HAD TO BETRAY HIS BEST FRIEND"

[Andy]

P.S. I miss the days when K-Mart had a decent SF selection

[Michael]

That is it! What's really embarrassing is that when I searched on the tagline it popped right up (I guess I was being too clever with my Googling and was trying other variations). And I see it was yellow circles. Have a great day!

[Andy]

Glad to help.