When you study 19th Century Radical Thought the concept of Progressive or Liberal thought, (Left), is associated with nationalistic aspirations. Progressives wished to do away with the monarchies and looked to the American Revolution as the mechanism to accomplish this change.
That's why it is odd to equate the Right with Nationalism!
Is the term nationalism, like fascism, so widely used and misused that it doesn't mean anything in the vernacular?
"My country right or wrong" strikes me as nationalism and is a mantra of the right.