East German border guards look through a hole in the Berlin wall after demonstrators pulled down one segment of the wall at Brandenburg gate Saturday, November 11, 1989. Lionel Cironneau | AP

The most significant hopes and gains unlocked by the Berlin Wall's fall, which was 30 years ago Saturday, are all at risk. They included a historic expansion of democracies and open markets, a wave of globalization that created the greatest prosperity and largest global middle class the world has ever seen, and the enlargement the European Union, to 28 from 12 members, and NATO, to 29 from 16 – deepening ties among the world's leading democracies. That all brought with it the hope of what then-President George H.W. Bush called in 1989 "A Europe Whole and Free," in which Russia could find its proper and peaceful place. Bush went even further in September 1990, after the UN Security Council had blessed the U.S.-led coalition's war to free Kuwait from Iraqi invasion, envisioning a New World Order, "an era in which the nations of the world, East and West, North and South, can prosper and live in harmony." The idea had been hatched a month earlier by President Bush and General Brent Scowcroft, his national security adviser, while fishing near the president's vacation home at Kennebunkport, Maine. They came home with three bluefish and an audacious vision that the Cold War's end and the Persian Gulf Crisis presented a unique chance to build a global system against aggression "out of the collapse of the US-Soviet antagonisms," in the words of General Scowcroft. Reflecting on those heady days, Scowcroft recently told me that he felt everything he had worked for in his life was now at risk. If U.S. and European leaders don't recover the common purpose they shared at that time – and there is yet little sign they will – this weekend's Berlin Wall anniversary is more a moment for concern than celebration. "Look at what is happening in the world," French President Emmanuel Macron said in a freshly published interview in the Economist. "Things that were unthinkable five years ago. To be wearing ourselves out over Brexit, to have Europe finding it so difficult to move forward, to have an American ally turning its back on us so quickly on strategic issues; nobody would have believed this possible." This weekend's 30th anniversary of the Berlin Wall's fall provides a good moment to reflect on four reasons that event – one of freedom's greatest historic triumphs – has failed to deliver on its full potential. Understanding that, might unlock a better path forward.

1. China's authoritarian turn

Another thirtieth anniversary this year, the crushing of the Tiananmen Square protests in June 1989, might have had even more lasting consequences. The regime's attack on the pro-democracy movement, at a time when the Communist Party could have chosen greater liberalization over repression, ensured that the most important rising power of this century would be increasingly authoritarian in nature. The lesson Beijing took from the Cold War's end was that the Soviet Union had failed because it had liberalized its economy too little and its politics too much – a fatal combination. Economic liberalization and a growing Chinese middle class failed to bring with it the Western-style democratic freedoms that some thought would follow. That doesn't mean a New World Order can't still be built with Beijing, but it will take considerable vision and patience to knit the two most important countries of our times together simultaneously, as strategic competitors and collaborators.

2. Revanchist Russia and the 'Gray Zone Conflicts'

There's a lot of finger pointing still about "who lost Russia" after the Cold War, whether it was Westerners who didn't offer enough of an embrace or Russians who missed the opportunity. Wherever you stand in that debate, the U.S. and its European allies failed to appreciate the potential or staying power of Putin, who has made it his life's purpose to redress what he considered the biggest disaster of the 20th century, Soviet collapse. At the same time, the enlargement of the European Union and NATO left behind a "gray zone" of 14 countries like Ukraine that were no longer in the Soviet bloc or Warsaw Pact but hadn't been integrated into Western institutions. French leader Macron has argued that it would be a huge mistake not to work to find more common ground with Russia. The difficulty is how to do so without selling out the democratic, sovereign hopes of Russia's neighbors.

3. Europe's lost momentum

Bill Emmott argues in Project Syndicate this week that the European Union's biggest problem "is not Euroskepticism but indifference." He's partially right: some 72% of French respondents in an opinion poll based on interviews with over 12,000 respondents across the 28 EU countries don't think they would miss the EU as well as 67% of Italians and 60% of Germans. That said, the EU also suffers from not having addressed design flaws that hobble it even as it has grown to its current size of 28 member states with 513 million citizens and a GDP of $18.756 trillion. They include a monetary union without a fiscal union, immigration policies that allowed free movement inside the so-called Schengen Zone but too-porous external borders, and a failure to envision a world where the U.S. is losing interest, Russia remains a problem, and China is remaking global politics and economics. Europe is "on the edge of a precipice," Macron told the Economist. "If we don't wake up … there's a considerable risk that in the long run we will disappear geopolitically, or at least we will no longer be in control of our destiny. I believe that very deeply," he stated.

4. The lack of US vision and strategy