Thanks for clearing up the facts around this. I updated my comment above.

This seems like an attempt to undermine NATO. The only time article 5 has been used was after 9/11.

By saying Europe had a choice and should have resisted, he lays the foundation for the US to not follow through on their NATO commitments.

Edit: The commenter below is right, the article 5 was used for Afghanistan, not Iraq. My whole argument is thus invalid