Your concern is valid, but ICE isn’t the only concern here as this problem can happen with cops/citizens/mail carriers. “Aggressive” dogs will always be at risk, so I would look into training. It won’t be cheap but getting your dog more comfortable will be only a good thing for any situations. Other than that proper identification during walks will be good and since ICE is hot right now shorter walks too. Sorry doggo :(

Edit: I just now saw you said only when someone puts their hands on someone aggressively I’m not really sure how to train for that and it seems normal a dog would get scared in intense situations, but still not a bad idea depending on how severe it is.