Nile Gardiner is the director of the Margaret Thatcher Center for Freedom at the Heritage Foundation and a former aide to Margaret Thatcher. The opinions in this article are those of the author.

(CNN) In just two months' time, the world will bid farewell to President Obama. In his final overseas trip before exiting the White House next January, Mr. Obama stood alongside his German counterpart Angela Merkel at a press conference in Berlin , warning against a "meaner, harsher, more troubled world."

In the wake of last week's stunning electoral victory by Donald Trump and the Republican Party, he seemed a diminished figure, as did Mrs. Merkel, the guardian of a liberal ancien regime that is beginning to crumble on both sides of the Atlantic.

The winds of change are sweeping through the West, challenging decades of conventional wisdom, overturning the dominant liberal consensus, and reviving a greater sense of national identity and self-determination. Without a doubt, the extraordinary victory by the Vote Leave campaign in Britain's EU referendum was a precursor to the November presidential election in the US, with an emphatic humbling of the political establishment against all odds and all expectations. Though the Brexit campaign was in many respects different to that of Mr. Trump in both style and messaging, both succeeded in delivering a political earthquake that shook the global political order.

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Above all, the Brexit victory was a huge blow to the European Project and the idea of supranationalism. Europe's ruling elites, from Brussels to Paris and Berlin, fear its impact, with the potential unraveling of the entire EU over the next couple of decades . If Brexit is a success, as seems increasingly likely, others will follow. And the US will now likely play an important role in helping to ensure that Brexit works, with the new President and a Republican-dominated Congress in favor of a US-UK free trade deal.

Britain's vote to leave the EU was not only a defeat for the Eurocrats, it was also a slap in the face for President Obama himself, who had invested heavily in supporting the Remain campaign, with his menacing threat of Britain being at the "back of the queue" for a trade deal if it voted for Brexit spectacularly misfiring.

The Brexit win demonstrated that sovereignty matters and that attempts to suppress it will fail in the long term. It is hard to believe that the European Union will survive in its current form, with increasing tensions over the refugee influx, a mounting eurozone debt crisis, and a growing Islamist terror threat assisted by gravely inadequate border controls.

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Supranationalism goes against the grain of history and human instinct, and will surely go the way of the dinosaur. But it must not be replaced by isolationism or protectionism, and to their credit the leaders of the Brexit movement presented a vision for Britain that revolved around free trade, free markets and assertive leadership on the world stage, centered upon core alliances. Those alliances include the Anglo-American Special Relationship and the North Atlantic Treaty Organization.

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Against the backdrop of an increasingly dangerous world, with the rise of ISIS, a resurgent imperial Russia, and the prospect of a nuclear-armed Iran, the US and Great Britain must be prepared to lead.

At the end of the day, it is nation states that will stand up to terrorism and tyranny, and not the grandiose dreamers sitting in the European Commission or the European Parliament. Europe's liberal ancien regime is dying, and its leaders must adapt to the new reality and embrace change, or continue to steer a sinking ship.