There's always been something universalizing about the Internet. The World Wide Web has seemed both inherently singular and global, a sort of ethereal United Nations. But today, as Scott Malcomson contends in this concise, brilliant investigation, the Internet is cracking apart into discrete groups no longer willing, or able, to connect. The implications of this shift are momentous.

Malcomson traces the way the Internet has been shaped by government needs since the 19th century - above all, the demands of the US military and intelligence services. From World War I cryptography and spying to weapons targeting against Hitler and then Stalin, the monolithic aspect of the digital network was largely determined by its genesis in a single, state-sponsored institution.

In the 1960s, internationalism and openness were introduced by the tech pioneers of California's counter-culture, the seed bed for what became Google, Microsoft, Facebook, and Apple. But in the last 15 years, security concerns of states and the privatizing impetus of e-commerce have come to the fore and momentum has shifted in a new direction, towards private, walled domains, each vying with the other in an increasingly fragmented system, in effect a "Splinternet".

Because the Internet today surrounds us so comprehensively, it's easy to regard the way it functions as a simple given, part of the natural order of things. Only by stepping back and scrutinizing the evolution of the system can we see the Internet for what it is - a contested, protean terrain, constantly evolving as different forces intervene to drive it forward. In that vital exercise, Malcomson's elegant, erudite account will prove invaluable.