Critically, he told an audience, the history of the institutions had allowed them to build up trust with members of the public.
"I was surprised, and continue to be, how many smart people ask me in all seriousness 'do we really still need these library things in this age of smart phones, search engines' and so on?" he said.
Real-life libraries could outlast the internet, Roly Keating says (AP)
"And I have to say, it is a serious question at a time of public policy over investment. And what we collectively believe libraries are and are for will determine what form they survive in."
He added: "This feels a pretty brutal choice that we are allegedly confronted with. And it won't surprise you, here at a gathering like this, that I think it's a false contradiction and an utterly false choice to make.
"When we talk about libraries, I'm told about the old values, the traditional values of these institutions. Some believe they are being replaced by new ones about being more open and connected and virtual.
"And of course our belief, passionately, at the British Library is that it's about both. And that's the great richness of what a library is and can be."
Speaking of how libraries could and would flourish in a society obsessed with the internet, Mr Keating added her had been "very struck" by the strength of global networks dedicated to the preservation of information.
"They stand for a certain freedom, and privacy of thought and search and expression," he said of libraries.
"They stand for private study in a social space; they are safe, they're places of sanctuary and play a vital role in some of the poorest communities. And they are trusted.
The internet will not override the need to trusted libraries, Mr Keating says (Alamy)
"Our commercial partners in the information delivery space do wonderful things and we couldn't live our lives without them.
"But the time frame we think on, centuries back and centuries into the future, allows us to think about trust in its highest sense, and authentication and provenance of information, and digital information in particular.
"Those are hard-won privileges and values and they're worth defending."
He added: "With all our fascination of and love for the internet in the age of data, these values and the values and idea of the library predated the internet and if we get it right may yet outlast it.
"And in some ways they are the most powerful and resiliant network of all, if we continue to believe in them."
A Princeton PhD, was a U.S. diplomat for over 20 years, mostly in Central/Eastern Europe, and was promoted to the Senior Foreign Service in 1997. He has taught courses for many years at Georgetown University pertaining to propaganda and public diplomacy. He currently shares ideas on the theme "E Pluribus Unum? What Keeps the United States United" to Eurasian/European delegates participating in the "Open World" program.
Brown’s articles have appeared in numerous publications. A recent piece is “Janus-Faced Public Diplomacy: Creel and Lippmann During the Great War” (published in Nontraditional U.S. Public Diplomacy: Past, Present, and Future).
He is the author (with S. Grant) of The Russian Empire and the USSR: A Guide to Manuscripts and Archival Materials in the United States. He also served as an editor/translator of a joint U.S.-Soviet publication, The Establishment of Russian-American Relations, 1765-1815.