You're on the internet;
try using it sometime.
My nationalism is also motivated by practicality. I think the world is moving towards a gradual unification, in 100 to 200 years, and whoever is in charge at that point will determine the course of human society and government as humanity leaves Earth. I prefer the American model to the alternatives, and I am not afraid to say so, or to defend that assertion. If there were a better model, I would advocate it. There isn't one, so I don't. If you would like to argue that humanity would be better off with Russia or China leading the world than with America doing so, feel free to make your case.
If you don't, then you too should also hope to see the American reign continue in a multilateral fashion with Europe, because it is the only system that provides the backbone to the democracy and freedoms you enjoy. The whole "can't we all just be friends" argument of everyone being equals is a ridiculous teenage fantasy-interpretation of the world and I won't even bother shooting it down, so I'd prefer if nobody makes it. In human societies there will always be leaders. In the global political stage, I like that leader being America, and I would like it to continue being America, because I don't like the idea of somebody putting polonium in my hot chocolate or having to reroute my IP through Sweden to view my favorite websites.