Yesterday marked the 30th anniversary of the Berlin Wall’s collapse. Its ruin would pave the way for the end of the Cold War and mark the abject failure of communism.

Throughout history, people of every color and creed have sought to flee the reach of communism. Tyrants know this, which is why the Berlin Wall was built — not to keep people out, but rather to keep people in.

Throughout the Berlin Wall’s existence, the Soviet Union’s communist regime in East Germany imprisoned and killed thousands of people yearning for freedom.

America did not bomb the Berlin Wall to the ground, or send in tanks to demolish it. Instead, the Wall’s collapse came as a result of peace through strength: rebuilding America’s military, pioneering missile defense technology, bankrupting the Soviet Union, and speaking truth to the oppression of the “evil empire.”

In 1987, President Ronald Reagan had stood before the Brandenburg Gate and made the simple yet transformational demand: “[I]f you seek peace, if you seek prosperity ... Mr. Gorbachev, tear down this wall!”

Three years later, the Berlin Wall fell to the ground. Speaking the truth caused the tyranny of East Berlin to crumble.

American values have immense power in advancing the cause of freedom.

Though the physical, graffiti-covered, concrete barrier was toppled in East Germany, modern Berlin Walls still exist today. Tyranny oppresses billions across the world — especially in China.

As the Chinese Communist Party continues to encroach on the autonomy of Hong Kong and eliminate the democratic norms there, the cause for freedom has never been greater.

Today, Hong Kong is the new Berlin.

China poses the most significant long-term geopolitical threat facing America and our allies. It is modernizing its military with stolen American technology and intellectual property, and China is using economic blackmail to coerce its neighbors and countries around the world.

And much like the people in the Soviet bloc experienced, the Chinese Communist Party engages in routine censorship and surveillance of its citizens and commits atrocious human rights offenses. They have created a 1984-style dystopia, with pervasive surveillance powered by innovative technology. Millions of detained Uighurs and other religious minorities are languishing in concentration camps while Falun Gong practitioners are allegedly murdered so their organs can be harvested.

As a member of the Senate Foreign Relations Committee, I’ve sought to highlight and counter how the party runs that dystopia. I’ve sponsored legislation and urged the Trump administration to block China’s access to American technology companies that provide DNA, voice and facial recognition tracking of minorities such as the Uighurs. Recently, the administration implemented my recommendations, and I applaud President Donald Trump for doing so.

All tyrants, including those of the Chinese Communist Party, fear the truth. And they fear dissidents.

As the son of a Cuban political prisoner, I know firsthand the power dissidents and their stories hold, and I have sought to shine a light on oppressive regimes around the world and to fight for those yearning for freedom.

While many Americans are familiar with Houston Rockets general manager Daryl Morey’s tweet signaling support for the Hong Kong protesters that sent the party into a tailspin, many may not be familiar with the story of the late Dr. Liu Xiaobo.

Dr. Liu was a pro-democracy advocate and Nobel Peace Prize winner who was unjustly imprisoned by the Chinese government for publishing “Charter 08,” an anti-Communist manifesto calling for political freedom and human justice in China.

I worked to shine a light on his plight, hoping to shame the party into releasing him, including through legislation that would have renamed the street in front of the Chinese Embassy in Washington, D.C., Liu Xiaobo Plaza. To the deep dismay of the party, my legislation overwhelmingly passed in the Senate, without a single vote against it.

Though the Chinese government acted too slowly to release Liu Xiaobo before he died in captivity, I continued to press them to release his wife, Liu Xia, whom they were also holding. And, in July 2018, they did.

What led to Liu Xia’s release was not an aircraft carrier pulling up along the Chinese coast, or American tanks rolling across the border. It was simply light and truth.

In October, as one of the first U.S. senators to visit Hong Kong since the marches began, I had the opportunity to meet with pro-democracy activists, dissidents and protest leaders there. I dressed in black in solidarity with them, and we discussed the critical importance of protecting Hong Kong’s autonomy, free speech and basic human rights.

Freedom from the tyranny of the Chinese Communist Party is the battle cry of dissidents in Hong Kong. What have they been waving? American flags. And what have they been singing? The American national anthem.

In the United States, it is easy to take for granted the rights that have made our country a shining beacon of freedom. But all Americans, including those employed by our sports leagues and our corporate giants, should remember that our unique defining principles have the power to tear down oppressive walls, topple tyrannies and promote freedom.

Because, as Reagan demonstrated, truth is powerful and can transform the world.

Ted Cruz is a Republican U.S. senator from Texas and a member of the Senate Foreign Relations Committee. He wrote this column for The Dallas Morning News.