No chance.
How can you support your country of birth and not be nationilistic?
that's an interesting rationale but i dont think it's quite so straightforward, necessarily
if you asked any of my friends whether i was nationalistic, i know 100% all of them would you give you an odd look for even asking that question and say 'not remotely'
yet i do support (as in, they're the team i want to win - no flags, singalongs or any of that bollocks) england, so it could definitely be said i am in that regard
but, when i grew up watching football, you only ever saw players from GB unless they screened a euro cup final, that would get on the telly. so pretty much every player i actually knew (via match of the day, mainly, tho there were other outlets such as The Big Match)) were british and the majority were english, so it was pretty obvious i was going to support england in world cups - tho via world cups i grew to like individual players in those comps more than english players, often - eg pele, kempes, cruyff come to mind immediately
so yes i support england, dont feel nationalistic in the slightest, and have no sense of national pride generally, tho have no problem with those who do, you are what you are, i dont give a fuck either way really, unless you're a c*nt, cos all i care about in the end is 'are you a decent human?' yes? sweet, crack on