File this under the weird rules department. Did you know that according to 27 CFR 5.42(b)(7) of the TTB regulations for distilled spirits:
Labels shall not contain any statement, design, device, or pictorial representation which the appropriate TTB officer finds relates to, or is capable of being construed as relating to, the armed forces of the United States, or the American flag, or any emblem, seal, insignia, or decoration associated with such flag or armed forces;The only TTB ruling I found dealing with this provision involved a retailer who wanted to put stickers on bottles "bearing the slogan 'Fight Communism' and pictures of the Statue of Liberty and of the American flag with its staff transfixing a bleeding serpent." Classy! The TTB nixed the flag but said the rest of it was good to go, so I guess bleeding serpents are okay.
Of course, as with most rules, the TTB seems pretty lax about it these days, letting at least a few flags and military themes slip through.