Wings of Liberty Plot Analysis: Mar Sara

In this series of reviews I will be examining the plot of the various groups of missions in Starcraft 2: Wings of Liberty to highlight retcons, poor plots, and illogical decisions. Where relevant I will compare SC2 to SC1.

My main issues with the plot of Mar Sara mission are:
1) Why are Mengsk and Raynor now enemies?
2) Why is Raynor on Mar Sara in the first place?
3) Why doesn't Raynor try to help the people who have already been sent to the dig site?
4) Would the Dominion be able to defend Mar Sara if Raynor hadn't destroyed their bases?

For more information about the problems with the plot of Wings of Liberty I recommend these threads:
http://sclegacy.com/site/editorials/7-reviews/1134-scl-reviews-wings-of-liberty
http://sclegacy.com/editorials/6-speculation/906-starcraft-retcons-analysis

I'd like to thank Andy Cormack for letting me use his SC1 clips.
http://www.youtube.com/user/GroundXaero