SOCOM: U.S. Navy SEALs Confrontation
43 Achievements
PS3
EXPEDITIONARY MEDAL
PLAY 50 GAMES AS A MERCENARY PLAY 50 GAMES AS A COMMANDO/SPECIAL FORCES
11.0%
How to unlock the EXPEDITIONARY MEDAL achievement in SOCOM: U.S. Navy SEALs Confrontation - Definitive Guide
This will be relatively easy. Just play until you have 50 games with one group, and once you have that, try to get into games as the other group.