isn't that the difference between patriotism (what you're in favor of) and nationalism (what you're not in favor of)?

I dunno. To me it would seem that they're basically synonymous unless you're referring to the extreme. If that's the case, I'm opposed to the extreme.
Nationalism is essentially taking pride in your country because you were born there rather than because it's a country worth taking pride in. It's spoon-fed to you your whole life, especially in the US. You don't support our troops? You don't stand for the flag and take your hat off for the anthem? You're a communist bastard and you're un-American. That's nationalism and it's bullstuff.
That doesn't sound exactly like what patriotism/nationalism is. I mean I don't know what to call it but I'm opposed to that too. One of the reasons I take pride in my country because it principally allows its citizens to exercise that freedom not to support every aspect of it.
Actually, considering what I said to Jairo that would seem like some extreme form of nationalism, but not to the same degree of stuffting on other countries.