I can see where you're coming from, but I don't think the idea of a united Europe is that unrealistic. France and Germany used to be mortal enemies, but now the idea of war between the two is unthinkable. Already in most of the EU the English language acts as a lingua franca. You can visit most EU countries them without being able to speak the native language and still be able to get by. The EU's current population of 500 million people would make it the third largest country on Earth if it were to fully federalise.Fuck that, just lock arms with the U.S. The U.K. is practically our puppet state anyway. At least then they actually get to vote on all the wars we drag them into. The EU is not and never will be relevant on the international stage. The last few years have solidified that much. You can't just throw a super state on top of a bunch of countries and expect hundreds of years of history, culture and bad blood to melt away. And the EU isn't going to keep out the kebabs and Pajeets because it keeps inviting more of them in. If that's what you are counting on, you haven't been paying attention to the last five years.
Yes, the EU has a major problem in terms of dealing with the influx of non-Europeans wanting to live here, but this could be reformed. Opposing the entirety of the EU just because it has a soft touch approach to third world migration just seems like throwing the baby out with the bathwater to me. If nationalists were willing to work within the EU's bodies to affect these policies instead of refusing to participate then a lot could be done to fix this. By refusing to participate within the EU and writing the EU off as a tool of globalisation and multiculturalism, nationalists are ceding the EU's tools of power to the people who do support those things. It's a self-fulfilling prophecy.
And the last thing I'd want is for the UK to be at the mercy of the US. Although we speak the same language as them I'm worried that they would have no regard for our interests, and that any kind of arrangement with them would be a one-way street. Donald Trump's "America first" approach means that he will think nothing of exploiting us in whatever way he sees fit. Outside of the EU we are alone and vulnerable and the US will crush us like a bug, but if we still have the backing of the rest of Europe behind us then we will still have some bargaining power.