(I've done network security stuff for DoD and for some agencies, but you may have more experience on the classified side than I do, and what relevant experience I have I'm not going to give up to Hacker News and the Google index.)
And again: the NSA has done absolutely nothing to ensure that adversaries can't shut the power down in major cities, disrupt the GSM infrastructure, or cause billions of dollars in economic damages by messing with electronic markets.
And again: we have no specific knowledge that any branch of the military or intelligence has that capability to inflict on an adversary today.
Is there substantial overlap here with NSA? I'm 100% sure there is. But NSA is managed very differently than DoD.