The Forever War, by Joe Haldeman, has both sides in the conflict sending spaceships at .99c to where they think the enemy will be.. with the unfortunate reality

The Forever War, by Joe Haldeman, has both sides in the conflict sending spaceships at .99c to where they think the enemy will be.. with the unfortunate reality that if the enemy has populated & developed from that location first, the arriving fleet will be thousands of years of innovation behind and be wiped out without a chance. Written by a survivor of the Vietnam War and a frighteningly poignant read. "'The laws have changed sir, you no longer get a discharge after 1000 years. We're shipping you back out in 2 weeks' and of course the bastards only pay you for your subjective time, otherwise we'd have soldiers getting rich" https://en.wikipedia.org/wiki/The_Forever_War https://en.wikipedia.org/wiki/The_Forever_War