Well, I can't think of an example where a small country surrounded by an alliance of states had a working union with a far bigger (geographically separated) country except for colonial relations. Even if you can think of one, it just doesn't seem wise to be (more or less) isolated from one's neighbors and I don't think Russia holds more of a promise for Serbia than the EU politically, economically or regarding rebuilding and long- term peace. I don't say it couldn't work, but I doubt it would be the better choice.

On the other hand, I can understand why Serbs don't trust the EU anymore. The Kosovo war was fought mostly to redefine NATO as an offensive alliance IMHO, and it's sad that people still suffer from that shortsighted action.

"If you know your enemies and know yourself, you will not be imperiled in a hundred battles." Sun Tzu