U.S. Ambassador Joseph Kennedy, left, with British Prime Minister Winston Churchill outside 10 Downing Street in London on Oct. 17, 1940. (AP)

Since Britain voted to leave the European Union, there has been much discussion of Brexit’s economic and financial implications as well as its political consequences for Britain. What will happen to Labour and the Conservatives? Does this mean the end of the United Kingdom?

Less thought, however, has been given to Brexit’s effect on the future of democracy in Europe. European integration was an integral part of the foundation upon which Europe was reconstructed after World War II. Brexit signals and will probably further the erosion of this foundation, which undergirded the most prosperous, peaceful and politically stable period Europe had ever known.

It is easy to forget that democracy in Europe is a relatively recent development. Up through the middle of the 20th century, Europe was the most turbulent region on Earth, convulsed by wars, economic crises  and sociopolitical conflicts. To prevent a recurrence of these patterns after 1945, European leaders thought that a transformation at the domestic, international and regional levels was necessary.

Domestically, Europeans built a new type of political economy designed to ensure economic growth while also protecting societies from capitalism’s most destructive and destabilizing tendencies. They rejected the argument that government influence over economic life ought to be held in check and declined to simply leave markets to their own devices on the assumption that they could govern themselves. Instead, states took on a mandate to protect social stability and, with it, democracy. Internationally, the United States built a new security order, exemplified by NATO, designed to protect Europeans from external threats as well as themselves. The United States also helped build multiple economic and financial institutions to support Europe’s postwar reconstruction and future economic growth.

Supporting democracy was a key motivation for the project of European integration, which led to the E.U. Integration was supposed to promote economic development and generate the growing connections among the continent’s citizens that would make a common future possible. Postwar economic reconstruction, for example, could not be accomplished by the uncoordinated efforts of individual governments. A larger, more open European economy was necessary for sustained growth.

In addition, reconstruction had to be complemented by peace, which meant finding a way to reconcile Germany with Europe and vice versa, and instilling in Europeans a sense of community that would make warfare unimaginable. In Winston Churchill’s words, “to bring [Europe’s horrible history] to an end, it would be necessary to re-create the European family … and provide it with a structure under which it can dwell in peace, safety and freedom.” The goal was the creation of a “continent so integrated, so connected that war would be impossible.” Regional integration was thus seen as the third pillar of a postwar order that would ensure that the nationalism, extremism and internecine conflict that plagued Europe in the past never returned.

Initially, this postwar order worked remarkably well. The three decades following World War II remain Europe’s fastest period of economic growth. Although the Soviet Union remained a threat, the shift from hot to cold war was a major improvement over the bloody warfare of the past. Democracy flourished.  The economic growth of the postwar era seemed to offer something for everyone, helping eliminate the belief that democratic states could not or would not protect the interests of all groups in society. As a result, both workers and employers became far less radically opposed to one another after 1945 and became more willing to cooperate.

European party politics also changed dramatically. From the late 19th century through the interwar years, European politics had been riven by extremism of both left and right. World War II helped discredit the radical right, and after 1945, communist parties in the West gradually normalized politically, becoming more committed to democracy, laying aside insurrectionist methods and slowly distancing themselves from the Soviet Union. Over the course of the postwar years, the nationalism and extremism that had made stable democracy so difficult to achieve in Europe during the 19th and early 20th centuries gradually disappeared.

Unfortunately, things started to unravel in the 1970s. After 30 years of growth and progress, European political economies sank into a noxious mire of unemployment and inflation. Meanwhile, European integration had produced a highly integrated and interdependent economy but no corresponding political authority capable of directly responding to citizen demands or building the sense of community the E.U.’s founding fathers assumed would develop. When the United States abandoned the last remnants of the gold standard in the 1970s, throwing the international monetary system into turmoil, Europeans decided to move forward with monetary cooperation and, eventually, integration under the single currency of the euro.

The euro deepened Europe’s political deficit at a time when the spread of neoliberalism was already limiting the authority of national democratic governments. European monetary union deprived national governments of a critical tool of economic policy (countries could no longer devalue their currencies to boost exports, for instance) and shifted authority to a European Central Bank free from political, let alone democratic, oversight.

By the early 21st century, many Europeans were thus already wary of an E.U. that they saw as out of touch and unresponsive. Since European integration and monetary union in particular had robbed national governments of significant power and autonomy, many Europeans came to see their own governments as out of touch and unresponsive as well.

It is not surprising that anti-E.U. sentiments were particularly strong in Britain. The region long had an uneasy relationship with Europe, intimately tied to it, yet geographically removed from it, and with a “special” relationship with its former colonies (including the United States) that gave it at least the illusion of belonging to an alternative community. Britain joined the E.U. relatively late, in 1973, and was always an awkward partner, opting out of monetary union and other European initiatives.

Against this backdrop, the E.U.’s inability to solve or really even formulate coherent responses to the recent financial and immigration crises made an already-wary British population warier and emboldened nationalist and populist forces in Britain that had long worked to fan resentment against the E.U. and other “outsiders.”

Brexit reflects the way in which the postwar order has been eroded in Europe. It is likely to accelerate this erosion further. Brexit will encourage nationalists and populists in other parts of Europe and confirm the sneaking suspicion of many that the E.U. and other “outside” forces are to blame for their countries’ problems.  The uncertainty generated by Brexit is also likely to make it even harder for the E.U. to respond decisively to contemporary problems.

This is a very alarming time for students of European history and democracy. After 1945, the transformation of Europe’s domestic, international and regional arrangements brought prosperity, peace and political stability to the continent for the first time.

Europe’s version of social democracy has been under pressure since the 1970s. First, the collapse of the Soviet Union shifted the United States’ attention from Europe to other parts of the world. Now, European integration has faltered and Brexit threatens to set it back even further. The question the world now now confronts is whether prosperity, peace and political stability can once be again reconstructed in Europe but without the three pillars they have rested on since 1945.