Who could replace UK in EU?

Which country/countries could replace UK in EU? What do you think about such candidates as Serbia, Moldova, Ukraine, Belarus and Russia?

Define "replace".
Russia will likely never become part of the EU, and all the other countried put together could never replace the UK economically, politically and militarily.

In fact they would likely be a financial burden for a couple of decades at least.

I started writing the same reply before reading your words.


Impossible. Be serious.

I hope Serbia won`t. I hope Serbia replace EU in UK. I mean, we Europeans would stick together and, let us be frank, EU isn`t Europe anymore.

Possibly some special, limited membership for some of the forementioned countries have to be established which would allow them to gain full membership in a distant future? Something more advanced than present "Eastern partnership"? Something that would permit to travel and work in EU countries more freely, attract investments and gain experience in administration?

Ukraine for sure.