The sub-deal might be the trigger, but countries don't return ambassadors over a sub-deal. This can't be explained without underlying tensions. One big cause m

The sub-deal might be the trigger, but countries don't return ambassadors over a sub-deal. This can't be explained without underlying tensions. One big cause might perhaps be an 18 months travel ban preventing Europeans from visiting the US, a travel ban which separates families and has no justification anymore.