The United Kingdom dodged a bullet on September 18 as a wave of good sense in Scotland beat back the independence movement. But a 45% vote for independence in the world’s most successful multinational state after 300 years is hardly a ringing vote of confidence.

There is a lot of talk about devolution now in the UK, in part, because panicked Westminster politicians, suddenly realizing just how angry their arrogance and indifference had made the Scots, were willing to promise the moon to hold the UK together. And if Scotland is going to get more powers at home, it follows that England, Northern Ireland and Wales must have them too.

The most important lesson of the whole referendum may be this: that large and complicated political unions require decentralization and local control in order to survive. The centralizing, rationalizing impulse which imbues all great federal capitals with the desire to impose uniform laws and regulations across their territory—in Washington, in Brussels and in many other cities besides London—is something that needs to be kept within strict bounds.

The 20th century was an age of centralization. Industrialization made societies much more complex and increased the demand for uniform national legislation and policy, while the limits on communications and technology made the rise of large, centralized bureaucracies the most efficient and often the only feasible way to manage the affairs of large organizations. Moreover, with only a very small percentage of the population (only 1 or 2 percent early in the century, and not rising fast until after World War 2) having college educations, there was a shortage of people with the experience and breadth of knowledge necessary for many of the functions of government administration. Progressive ideology was all about creating effective bureaucracies and taking key issues out of politics and handing them over to (allegedly) meritocratic and apolitical administrators who would serve as the guardians of the public weal.

The 20th century was the golden age of the centralizing state, and the advanced industrial nations, including ones like the US and the UK where historically governments had been smaller and less intrusive, were marked by strong progressive and bureaucratic governments. This form of government had its problems and limitations, but it did many things well: improving public health and education, providing a framework for the development of a much more sophisticated and technologically advanced economy, organizing for victory in World War Two and the Cold War and so on.

However, in the 21st century it appears that the progressive ideal of the state will no longer suffice. A better educated and more sophisticated population is less willing to delegate important decisions to technocrats. Parents who feel they are as well or better educated than their children’s schoolteachers are less willing to defer to educational bureaucracies. Patients who surf the web want to understand their treatment options and look to doctors more as advisers than as authorities.

Additionally, in consumer societies people are used to getting satisfaction from their transactions with large entities. They refuse to stand in line for hours at the department store checkout counter, so why should they stand in line for hours at the Department of Motor Vehicles? As commercial institutions get better at providing services that are individualized and convenient, our expectations for the delivery of government services also rise. That puts great stress on centralized bureaucracies; making ‘customers’ happy is not the way that government offices and bureaucrats traditionally work.

Beyond that, advances in communications and information management technology both enable and require new methods of working. The immense power of these technologies—whether related to the ability of the state to monitor more and more of what citizens do or to the potential that the collection and processing of vast volumes of data offers—means that government now has more power that can potentially be abused than ever before. (This is not what the naive prophets of the technological age forecast, back when technology was going to free us up into a new kind of benign libertarian anarchy, but life is complicated that way.)

This creates a strong public demand to rein in states, but it also leads people to want centralizing states to return as much power as possible to the local level where people can exercise more control over their governors. And it puts particular pressure on large and complex units of government, whether these are multinational entities like the EU, or complex multiethnic or multicultural federal governments like those in the U.S. and the UK. The Scots have more reason to fear a remote and unaccountable London than ever before, and if they must be governed at all they want more of that government closer to home where it can be watched more closely and where Scots can feel more secure that their politicians share their cultural values.

This doesn’t have to mean administrative incompetence or chaos. In 20th century conditions, the economies of scale and the limited capacity of bureaucracies to function in the age of carbon copies and paper clips meant that the centralized state was the most efficient and in many cases the only possible way to manage the tasks of government. A giant and sprawling bureaucratic machine based in London, with all its faults and flaws, was a better UK solution than to cover the country with a multitude of rival, pettifogging authorities, wrangling endlessly over arcane rules. But in the 21st century we can be much more flexible. The IT that makes centralized government a greater menace to civil liberties than ever before also creates possibilities for local and limited governments to be more efficient and effective than ever before.

Cultural devolution is another 21st century trend that will both enable and drive political decentralization. The 20th century saw the hollowing out of rural and regional life in many countries. The great migrations from farm to city that drove the industrial revolutions meant that young talent clustered in the cities. The concentration of government and business in a handful of great cities meant that many of the best and brightest flocked to a small number of great cities, turning others into relative backwaters. London sucked the life out of Britain’s regional cities, and in the US cities like New York, Los Angeles and Washington flourished while others withered on the vine.

In the 21st century there are still uber-hot neighborhoods and cities, but regional cities (at least the ones that don’t allow corrupt political machines or hungry bureaucracies to choke growth) show real signs of revival. The internet gives professionals more freedom to live and work in cities like Chapel Hill or Aspen even as they sell their services on national and global markets. The internet also disperses culture and creates virtual communities that allow artists, writers and other creative people to interact with peers at a distance. Today’s young painters and filmmakers don’t have to live in the same neighborhood to benefit from seeing each other’s work and sharing ideas and techniques. The proliferation of universities also disperses talent; more and more regional cities have a critical mass of expertise, talent and creativity.

This is going to increase the demand for the devolution of government power as well as increase the capacity of regions to exercise it. States like Tennessee with hubs of innovation in places like Knoxville are going to want to run their own affairs and be able to do so at world class levels of competence in ways that would not have been possible 100 years ago. Scotland, Catalonia, Texas, Shanghai, Tamil Nadu: places like this that have regional cultures and identities are going to insist on more autonomy and they are also going to be better at exercising it. Wise national governments will find ways to support this healthy and stabilizing development; foolish ones will weaken themselves by attempts to block it.

Centralization was necessary and rational in the 20th century, and societies who could accomplish it effectively while limiting its side effects were the most successful. In the 21st century, effective devolution is likely to be the most important political and administrative task that advanced countries need to solve. Using IT to bring government closer to the grassroots without losing its coherence and effectiveness is the task that those who want to preserve large federal and multinational entities must learn to accomplish. The UK won’t survive if London tries to impose an increasingly powerful uniformity on the subdivisions of the Kingdom—and it also won’t survive if devolution imposes high costs on society, creates a more tangled bureaucratic web or fails to increase the efficiency and lower the cost of governance and administration.

What is true for London is true for Brussels and true for Washington as well. With its long history as a federal republic the U.S. will have an easier time making the transition than the EU, but effective devolution is the great political task of our times.

Meanwhile, for both sentimental and practical reasons, Americans can be glad that the Union Jack will not be coming down anytime soon. Once again, the people of Great Britain have demonstrated the moderation, practicality and respect for the rule of law that has made Great Britain the envy if perhaps no longer the dread of all the world.