In 1987, celebrating the 750th anniversary of its founding, the two sides of Berlin — the capitalist West and the socialist East — spent the year competing to see who could showcase the best cultural, historical and political events.

On a hot summer day in June, I was among the U.S. Army and Air Force officers at Tempelhof Air Field who watched President Ronald Reagan on TV give a long-awaited speech in front of the iconic Brandenburg Gate and the infamous Berlin Wall, built in 1961 to prevent East Germans from moving West.

When Reagan said, “As long as the gate is closed, as long as this scar of a wall is permitted to stand, it is not the German question alone that remains open, but the question of freedom for all mankind,” there was scattered clapping in the hall. Then, when the president exclaimed in his polished Hollywood voice, “If you seek peace … come here to this gate! Mr. Gorbachev, open this gate! Mr. Gorbachev, tear down this wall!” The group broke into cheers and prolonged applause.

After the speech, Reagan traveled to Tempelhof, where he joined a group of American officers and diplomats for a luncheon and made additional private remarks. To my surprise, Reagan revealed he had been holding secret but productive meetings over strategic arms reductions with Soviet leader Mikhail Gorbachev for months and had already asked him to make a major gesture of peace such as opening the Berlin Wall. Gorbachev responded that the wall was a German problem, and if East Germany decided to open the wall, the Soviets would not intervene. The diplomats, suspecting trickery, expressed their concerns to the president, who assured us he would “trust but verify.”

As an infantry company commander in the Army Berlin Brigade, I told the other company commanders I planned to put in a request to extend my tour immediately in order to be in Berlin when the wall came down. “You heard the Gipper,” I reminded them, “he just told Gorby to tear down the wall. So now it’s just a matter of time.” Everyone laughed as a fellow commander told me, “If you want to be here for that, you’d better plan on extending for a hundred years!”

My tour was extended, and the pressure for glasnost continued to build on the inflexible, aging regime in East Berlin. In 1989, Gorbachev publicly stated that the Soviets would not intervene in the reforms of other Warsaw Pact nations and in Hungary opened a section of its fortified border with Austria. Soon, East Germans started pouring through the Hungarian gap and holding weekly large-scale street protests in Leipzig and other cities demanding reform. Finally, on Nov. 9, 1989, tens of thousands of East Germans thronged to West Berlin with the opening of the Berlin Wall, and the party was on.

On the following cold Sunday night, they were heading home to the East, preparing to go to work on Monday morning with transformed lives. Three Americans, including me, had been standing for hours on the Berlin side of the Glienicke Bridge, famous for its Cold War exchange of spies, shaking hands and waving to the endless stream of people crossing the bridge back into Potsdam. German chants of “we are one people” filled the air. Many were holding West German beer cans in one hand and West German flags in the other, while others were staggering under the load of their purchases, carrying every electronic and food item unimaginable in the East and taken for granted in the West.

They greeted us with glee, offering chocolates and oranges along with their life stories. Everyone was happy. Three days ago, they were the enemy. In 11 months, they would be NATO allies. That’s how fast things can change.

On another hot day in June 1991, four years after Reagan’s speech, the wall was being removed, and Germany had unified as one nation, under the Basic Law of the Federal Republic of Germany. I had been extended again and was now serving as a U.S. military liaison officer to the newly established headquarters in Berlin for the German armed forces. In that capacity, I attended a ceremony to reopen the Heiland church, on the Havel River, which had been closed for years because it was located in the “death strip” area close to the wall.

The pastor gave a brief sermon to dignitaries, including military officers and diplomats from Germany, the U.S., the U.K., France, and the Soviet Union. Afterward, musicians from the German military played a wind quintet by Johann Sebastian Bach. The ceremony embodied a rare moment in history: the allies and enemies of World War II and the Cold War sitting in church together in a tribute to peace.

Army Capt. Franz Burnier, second from left, at a ceremony with military liaison officers from France, the Soviet Union, Germany and the United Kingdom outside the Heiland church near Berlin in 1991. (Franz Burnier) Over the previous 18 months, what was once inconceivable had just happened, due to the peaceful protests and unified voice of the people, and a few enlightened leaders with the vision and courage to take appropriate actions embracing change.

Let us hope that process can now repeat itself in Eastern Europe and the Middle East. Will we learn the lesson of World War II — “never again” — or will we let recurring fights over territory, ideology, ethnicity, political ambition and retaliatory escalation drag us into World War III?

To honor Veterans Day and the memory of my grandfather, an infantry company commander who lost his leg in combat against the German army in late 1944, I hope our current leadership — American and European — will have the courage to say that “never again” means “never again.”

Franz Burnier is emeritus professor of English at the College of DuPage and a retired Army officer who commanded units in the 82nd Airborne Division, the Berlin Brigade and the 5th Special Forces Group.