It can be easy to draw hasty and incomplete conclusions about European suburbs if you don’t look closely. Many European cities have districts of single-family (and duplex) houses, and these often extend into municipalities outside the central city. It’s not difficult to find areas around Western European cities that we would recognize as suburban “bedroom communities,” complete with cul-de-sacs, private yards-gardens, big-box retailing near the highway, etc. In general, the lot sizes are smaller and the structures clustered closer together for reasons related to higher land costs, lower family incomes, and more acceptance of town planning authority than found in the US, with its vast reaches of land that isn’t particularly valuable for farming or ranching use.

When in the teens and 1920s public transport began to need the “socialism” of public ownership, Americans were wary and unwilling to take such a step. Nineteenth-century American cities had been laid out with wide streets and large building lots to encourage more “healthful” living patterns than found in the older industrial cities of Europe. All these factors, plus somewhat higher family incomes, caused auto ownership in the US to grow rapidly in the interwar period. By the end of the 1920s, Americans were buying single-family houses in suburban districts not even served by commuter trains, much less tram or bus lines.

We also can't totally discount the cultural differences between England—which got transmitted to some degree to the US—and the rest of Europe. The vision of owning a small version of a manor house with a broad lawn was more in the DNA of Americans than was a vision of an elegant high-ceilinged apartment overlooking an urbane boulevard.

For a worldwide historical view of decentralization, I recommend Robert Bruegmann’s book Sprawl: A Compact History.

You will be especially interested in the book Crabgrass Frontier: The Suburbanization of the United States by Kenneth T. Jackson. Jackson has a lot to say about the development of transportation and land speculation that made American suburbanization possible, as well as the widespread adoption of balloon-frame construction. I had a lot of trouble wading through a lot of his arguments, but if you're truly interested in the history of urban transit as it concerns suburbanization then you should have no problem.

I recommend reading Private Pleasure and Public Plight by Popenoe. It briefly compares two very similar cities, Seattle WA and Stockholm Sweden, and how they took different paths in urban design and public and private transit.

First of all, it's striking how these two metropolitan areas were basically similar in population size, geographic setting (both had plentiful land), and population makeup (homogeneous). Seattle ended up having a weak downtown area and a population that lived in detached, single-family houses while Stockholm became more compact with medium-rise, multifamily structures in an area held together by an excellent mass transit system, even though it has Europe's highest rate of automobile ownership (because the Swedes are very wealthy).

Due to a longer and stronger tradition of public planning and control over the use of land, the Swedes are now blessed with a city that is orderly and efficient and also thriving (not to mention well preserved). Because the Americans value limited government, self-help, and protection of individual rights, along with an inability to make collective decisions about land use, they are struck with extremely dispersed, low density cities with poor public transit and a heavy reliance of private automobiles; and worse of all, cities that spill out into the countryside rather than making a fine distinction between urban and rural.

Can you find the source for the decentralization to avoid nuclear destruction?

I studied urban planning and landscape architecture in the mid 1960's (literally just around the time of duck-and-cover)and this isn't ringing any bells. The Interstates were designed to move artillery and military around in case of military need. Are you conflating the two, perhaps?

The planned communities designed and built from the ground up in the US include Levittown, Reston VA and Park Forest IL. Those are post WW-II developments

You might want to check out Andrew Hurley's "Environmental Inequalities" if you feel like a narrowed focus on race relations and urbanization. It's been a few years but I remember it covering the politics of suburbanization as well, at least within the narrow scope of the community the book focuses on.

Look into Sam Bass Warner, he laid a lot of the groundwork for this type of urban history regarding transport and urban development. Also you might check out Adam Rome's Bulldozer in the Country Side, which explores the development of modern American suburbs with a specific focus on the environmental impacts. As for the European side of things, I'm not so sure.

Have a look at:

/r/urbanplanning and /r/transit