Canada wasn’t a US vassal in the narrow feudal European sense of the word
Or any other sense of the word.
doesn’t inspire much confidence after the Iran debacle,
I don't see how this has anything to do with Iran, except Trump is butthurt that none of his allies want to help him with his stupid illegal war.He has to beg just ti fill up planes and ships at European bases.This proves that neither Canada or any European countries are vassals to USA, but are independent free countries.

No they absolutely weren't. Commonwealth only worked to promote cooperation between member states. It was not like it had any real power over any of the member states.