I think Europeans will have more trouble with this than US citizens. The US has a huge amount of veterans from the major fights weve been in for a couple generations,So just about every prep group will have a few of their own. a small band of Afghan Vets arent going to be that devastating VS a group that has their own vets leading their security, remember its always easier to defend than attack.

Europeans, except for Russians and many former Eastern Bloc countries really have very limited military training and even more with none however their "core" units are long term professional soldiers that are VERY well trained. . Europeans also have a strong history of the Military being used against their own citizens.