As taut as Berg is in action sequences--and Lone Survivor's war carnage is brutally sensorial-- he is not that efficient in creating a sense of rhythm, and therefore, sustaining tension. It takes a good 55 minutes of mediocre characterization and operational planning before gunfire strikes, and the action also gets repetitive and never properly breaths. The dramatic emotion of the village scenes come too late.
Berg struggles to turn his admiration for the soldiers' struggle into something more than just a visceral physical experience. Lone Survivor is a solid American combat film outside of the historical context, but it's hard to separate the drum-beating from the quality acting and immersive cinematography.
Lone Survivor is utterly successful at showcasing the horrors of war. Not even in horror movies have I seen characters this relentlessly brutalized; the difference is these characters never stop fighting back. It's expertly made and extremely depressing.