Assignment: Earth seems like a bit of an anomaly in Trek history. For starters it has the Enterprise going back in time for research purposes. That seems like a rather dubious assignment from Starfleet. In fact, at no other point in Trek history (prior to the 29th century) does Starfleet seem to condone the casual use of time travel.
Secondly, Gary Seven's mission seems a bit odd given everything that we know about Earth history. They prevented the launch of an orbital weapon's platform but to what end? Spock talks about orbital weapons being a "problem"....why? Why does no one mention the fact that the Eugenics Wars are only 30 years away (and world war III is almsot a century later? This begs the question of what exactly was the Enterprise doing in 1968 anyway? The 60's are not a particularly traumatic moment in world history given everything that happens at the end of the 20th century and the middle of the 21st.
Secondly, Gary Seven's mission seems a bit odd given everything that we know about Earth history. They prevented the launch of an orbital weapon's platform but to what end? Spock talks about orbital weapons being a "problem"....why? Why does no one mention the fact that the Eugenics Wars are only 30 years away (and world war III is almsot a century later? This begs the question of what exactly was the Enterprise doing in 1968 anyway? The 60's are not a particularly traumatic moment in world history given everything that happens at the end of the 20th century and the middle of the 21st.