Backpack - Military Style/Pattern - Negative Attention?

I predict zero drama. I don't think the baby killers got around in cammo gear in the 80s, either. If you were sporting a crew cut, mirrored shades and went around introducing yourself as a "trade analyst" you would probably dredge up unhappier memories.

Probably stay out of the El Chorillo area of Panama City. The US bombed the poorest neighborhood and burnt it to the ground. They are still a bit pissed.

No problem with the pack but you will be treated better if you look clean and neat.. Teens in Guat are now wearing camp print pants. It used to be a no no for anything that smacks of the military but those days are gone.

You will be fine. patywolf is right about what teens there are now wearing. If anything, you might offend a European traveler who has an axe to grind against the United States. I have seen one travel blogger online who purposely puts an American flag prominently on his backpack, etc. so that people will try to speak English with him and so that people who don't like the US won't talk to him lol. I have seen retired Americans sitting in Parque Central in Antigua many times with VFW or American Legion hats, and no one seems to bother them.

If anything, you might offend a European traveler who has an axe to grind against the United States.
Really? Because the Euro is in free fall? They don't like Obamacare?

Put a Greek Flag on the backpack, everyone knows they are dead broke, nobody will mug you.

I just asked a European. He told me the whole world recession that still has great effects was caused by U.S. banks. It was a more detailed explanation but those bloody money exchangers have endangered US citizens around the world.
Maybe go with this look.
http://tinyurl.com/q3wssyw

First time Ive ever used the word, but.......... TROLLS.

This OP question was summed up nicely in the very first response. It is true that everything after that was superfluous nonsense.

Forum candy, as it were.