I'm also European and do not notice a difference between being fired and let go. In both cases your contract is terminated by your employer. If it's about meaning, the meaning is the same. Since we likely do not live in English speaking countries (I don't at least), it's difficult to map these words to any concepts that might exist somewhere else and say one is better than the other. A more European thing would be to actually forbid the employer to signal in any way why your contract was terminated, so that it interferes with your future career.