I'm a bit confused, if NSA mission is to be able to spy on other counties' military operations, why wouldn't that include the ability to intercept communications coming from outside the country or information going out from suspected spys? What I'm saying is the facility in NYC is not at all surprising, there are a ton of fiber cables that come in from overseas into NYC. Anyone with half a brain about internet infrastructure and has ever read any of the mission directives or legal authorities of NSA will realize exactly what they're doing there. That is looking at cyber operations/attacks coming into the country and looking for covert communications from people who are trying to influence our government for their foreign government's military or economic benefit.
Also, for what it is worth, NSA is also pretty important in ensuring weapons proliferation and military equipment movements (which helps indicate possibly wars, covert actions or invasions) using measurements of various types to track nuclear, biological and other weapons. That is fairly essential for upholding and enforcing international laws and treaties.
Finally I'm also confused when people say "domestic" tracking. Basically the NSA had databases they could look at if given legal authority to do so (meaning they think someone is a spy and show evidence of that) to see interactions between a person and other people (who they call, how often, where their phone is, etc). Apparently it seems now they just have to request or, like anyone else, buy that data from the telecoms instead of it being in house.