The good Lord reveals His mysteries in His own good time. He knows who is what. We all just have to hang on to whatever rags of sanity we can retain until He does. 
I for one would like to see many other countries standing with Israel against those who seek her destruction.
The problem I'm having with the issue of The Lost Tribes is simple: Many who espouse the theories set forth by LostTribe reject the notion that the Jews living in Israel today are true descendants of Jacob. They believe these "Jews" are imposters, laying claim to promises never made to them. A previous post by LostTribe engaged my radar.
Some who espouse these theories (such as Arnold Murray of The Shepherd's Chapel in Gravette Arkansas) go even further...it's my understanding that he believes that Jews are descendants of Satan. He calls them "Kenites," children of Caan, whose father was (according to Murray) the devil himself and who actually impregnated Eve.
I think it's important to know with what and with whom one is dealing when corresponding back-and-forth on a website like this.
I personally believe that Abraham's descendants are far greater in number than is usually supposed, but it's important to remember that his lineage includes Ishmael and Esau.
Whatever God will reveal will be revealed. If The Lost Tribes populated Europe and the Americas we will all know it eventually.
The good Lord reveals His mysteries in His own good time. He knows who is what. We all just have to hang on to whatever rags of sanity we can retain until He does.