The president does not have the authority to sign s hiding agreement without the Senate signing off on it. He knew that he couldn't get that approval so he signed a document he knew would not be binding beyond his term. Everyone including all those shocked and betrayed world leaders knew what he was doing and what his signature was worth without Senate support.
The US has a process for binding international agreements and they decided to circumvent it and all the drama now is staged and really not a concern. I have never seen an article were Europeans were worried about what we think about then. I really assess no reason to worry about what they think about us.