You can find English subtitles for Generation Kill , Season 1, Episode 1 ("Get Some"), which follows the First Recon Battalion during the 2003 Iraq invasion, on popular subtitle websites.
Complete .srt files, covering key dialogue from characters like Sgt. Brad 'Iceman' Colbert and Lt. Nathaniel Fick, are available to download from Subscene, OpenSubtitles, and Addic7ed. Generation Kill subtitles English S01E01