Likely as part of recruitment efforts. "Come be part of the green future, at the U.S.Army" or similar. Though, even if accidentally, this helps with emissions

Likely as part of recruitment efforts. "Come be part of the green future, at the U.S.Army" or similar. Though, even if accidentally, this helps with emissions (AFAIK, DoD vehicles don't tend to be subject to same emissions standards as us mere mortals), that would be a win, too.