User blog comment:PresidentEden78/Battle Blog 10: New Trailer, More Info on Singleplayer Campaign/@comment-99.10.178.107-20110910154626/@comment-2224289-20110911072234

^anon, it is shown clearly that the PLR is related to BF2's MEC, which with China started invading the US West Coast (right?)

That looks accurate, and they didn't even show the enemy look yet, which is interesting