Nationalism vs. Patriotism

The words "nationalism" and "patriotism" are used synonymously by some, while others (especially political scientists) see a difference. After being corrected for a comment I made recently (I used "patriotism" and was told I meant "nationalism"), I started trying to understand the difference betweent the two words.

I knew there was, generally a difference, just as there is a difference between "nation" and "state," and I believed (perhaps naively) that nationalism was love of/devotion to nation, while patriotism was love of/devotion to state. In the USA, most generally don't see a difference between nation and state (unless we are political scientists), though in some other parts of the world the difference is big and important.

So please comment on what you think the words mean, how they differ, and how they apply in the USA. This quiz is open book, but please cite accordingly!

Thanks!