Working on GovCloud requires ITAR which is citizen or "permanent resident" (green card). There are other positions that require a security clearance, but GovCloud does not. GovCloud is open to non-governmental customers who need to meet stricter requirements (it's not solely for government use).
I don't think it has much to do with "spy country". The area just happened to be one of the first to build a co-location/interconnect site where different providers could join their networks. Then, as the article states, "Networks build atop networks" and it grew from there.