I don‘t know too much about this but I kind of always assumed that even if there was perfect separation, one way for the NSA to get to the necessary data would

I don‘t know too much about this but I kind of always assumed that even if there was perfect separation, one way for the NSA to get to the necessary data would be through GCHQ as an agency in Europe which could help and share this data. It might be harder as the laws are different but still. Is it too paranoid to assume that or do I have completely wrong assumptions about cooperation between the Five Eyes.