My opening sentence for my SOP for a PHD in Urban Planning reads:

In my PhD, I want to examine the matrix of material, institutional and cognitive contexts involved in the urban development policy environment in Kabul, Afghanistan.

Is that too broad? I feel like one could write several dissertations on each of the three contexts that I present here. Should I be focused like, I want to examing the nature of informal housing in urban planning, or something really narrow like that? I want to get into the program and I imagine a focus will help me get in, But i also want to explore the broad topic I present above and find my focus eventually. Any thoughts?