If you try to look for a cause the countries in question seem to be in the EU block that is the source of much within-EU immigration tension. Immigrating to the

If you try to look for a cause the countries in question seem to be in the EU block that is the source of much within-EU immigration tension. Immigrating to the US legally is hard, and for someone with few opportunities in their home countries the incentives are higher to find a way to work immigrate to the US. Legal or otherwise. Incentives are different in each direction because working illegally in the rich EU countries is almost impossible, while it is normal in the US. If there is an underlying issue of overstaying when people come from some EU countries where there is an economic incentive to go to the US, then one can understand that the US will respond by imposing visa requirements to ameliorate that. Therefore if overstaying is not a concern when going from the US to the EU then imposing the same requirement in reverse is more of an emotional concern, which might be the right choice if ones goal is to have the EU act as a whole emotionally.