Other folks have covered this, but I've brought soda (and other non-carbonated soft drinks) back from abroad nearly every time I've flown back to the US - probably around a dozen times, and usually several containers. Never once had a bottle (glass or plastic) or can break or leak.

I've never been clear on whether they actually need to be declared, but seeing as the ag inspectors are generally rather humorless sorts, I always do just to be on the safe side.

"2x 1 ltr iced tea soft drink" etc.