-ground based military installations

-preexisting government

-means of communication (cables, radio towers etc)

-power generators

-population centers (limited, so as to keep enough people alive to maintain the world after occupation)

to cause disorder and suffering, making it easier for your forces to take over

In some instances it would demoralize the population in to submission. It's very akin to acutely complacent populations under oppressive tyrannical governments. Think about how corrupt and worthless the current US government is for example and the overall population of the US content to Twitter on their IPhones and ignore the truly disturbing crimes their government commits against them. And if you think I am blowing hot air then you need to seriously do some homework and perhaps watch Jessi Ventura's Conspiracy Theory (just know that they don't have ALL the facts and that they are just an investigative reporting show, with limited inside information which is just conjecture).