Yes, there does appear to be a growing malignance of nationalism on a global scale. I think the West has had a somewhat wishy-washy and inconsistent attitude when it comes to nationalism, and that's also been part of the problem. We apparently like nationalism when we're the ones who do the nation-building, but we also have to acknowledge the historical consequences of nationalism.
In a nuclear world, I don't believe we can afford the luxury of nationalism anymore. Even during the Cold War, both the West and the Soviet Bloc were internationalist in their scope. We considered ourselves part of the "Free World," emphasizing ideology over nationalistic concerns. Although that's where it got tricky, since the Cold War also involved nation-building and national liberation (such as when the colonial world started becoming independent nations).
I think too many in the West wanted to have their cake and eat it, too. We wanted all the benefits of having a global empire while telling the world that we were against that sort of thing. Every military engagement somehow becomes justified as "defensive," at least in the sense of defending US interests - which are all over the world.