In Europe is in Europe, and as well in Asia. I don't think the fraction is very relevant. And if history is important, the Ottoman empire has a history very much involved with the rest of Europe.
Think of Venn Diagrams, only part of Turkey is part of Europe. There's overlap, but one isn't inside the other. Turkey is, like Russia, considered a transcontinental country. They aren't "in" either continent, but part of them is.
> And if history is important, the Ottoman empire has a history very much involved with the rest of Europe.
As an adversary/attacker, yes. But that's not a reasonable foundation for declaring membership.
