What Happened to Central Asian Peoples?

Rodra Jit says that once the Central Asian people considered India to be the ancestral home and adored and followed Indian culture. But then how and when did they start considering India foreign place and attacked India countless times? Rodra Jit: These were Indian origin people who had gone out of India through wave after wave of migrations. And some of them became nomadic. We called them the Saka people, the Shaka people,. The West calls them Skitians. So what happened is the question.