By most accounts, Pope John Paul II played a major role in ending that divide, largely by focusing attention on injustices in his native Poland, then under Soviet sway.
Today, with the Vatican set to elect a new leader, the world stands divided yet again. The Cold War analogy is imperfect, but increasing tensions and violence are threatening what has been called a possible “clash of civilizations” between the Islamic world and the West.
Perhaps nowhere has that clash been bloodier than in Africa. Thousands have been killed in recent years in fighting in Sudan, Nigeria, and elsewhere -- often between Muslims on one side and Christians and animists on the other.
Robert Moynihan is a historian and editor in chief of “Inside The Vatican,” a monthly magazine that covers the Holy See.
"Africa is a place now where Islam and Christianity confront each other and are in relationship to each other in a kind of uneasy, sometimes intensely nervous relationship," Moynihan says.
Interfaith dialogue is a major legacy left by John Paul, the first pope to pray in a mosque and apologize for Christian persecution of the Jews.
Moynihan and other analysts interviewed by RFE/RL say they believe the next pope, following in that legacy, could help stem Africa’s violence -- and set a tone for Christian-Muslim reconciliation around the world.
Africa’s estimated 850 million people are currently nearly evenly divided between Muslims in the north and Christian and animists in the center and south.
But in recent years, Africa has become a vast shopping ground of souls for the world’s major religions. American Protestant groups, investing millions of dollars, have made vast inroads in some countries, such as Uganda, while the Catholic Church itself has seen the number of its African faithful triple to 147 million people over the last 35 years.
And then there’s Islam, which is winning converts from Ethiopia to Nigeria by investing billions of dollars in mosques, education, and other aid from rich Persian Gulf states such as Saudi Arabia.
"Islam apparently would like to be influential all across central and southern Africa, what we sometimes, perhaps wrongly, would call ‘black Africa,’" Moynihan says. "And Christianity, which became influential there under the missionaries of the colonial powers, would like to remain. And Islam is pushing southward and in Nigeria, the clash is very particularly visible."
At least 5,000 people have been killed in religious violence since 2000 in Nigeria, whose population of 130 million people is roughly divided between Islam and Christianity.
Human rights groups have condemned what they called the abuse of Shari’a or Islamic law in Nigeria’s 12 northern mostly Muslim provinces. They say such abuse ranges from random flogging and executions to failure to obey due process in legal proceedings.
Some analysts say the new Islam spreading in Africa is more militant than previous forms that have existed there for centuries, making it increasingly fertile ground for Al-Qaeda and other terrorist groups.
David Shinn of the George Washington University in Washington is a former American ambassador to Ethiopia and Burkina Faso who says newer strands of Islam are challenging traditional beliefs:
“In the last hundred years or so, they [Christians and Muslims] have been able to live side by side in a fairly cordial way. This is being disrupted to some extent by the influx of very strong Salafi or Wahhabi views coming primarily from the Gulf states, where they are bringing a form of Islam that runs counter to the traditional Sufi or mystical beliefs of most Africans,” he says.
Shinn emphasizes examples of religious cooperation in Africa, including January’s peace deal that ended 21 years of civil war between Sudan’s Muslim government and rebels in the Christian and animist south in which hundreds of thousands of people were killed.
But he says that Christian-Muslim dialogue -- and the continent as a whole -- would be better served if the religions themselves, in his words, “dampen down the competition” for African converts.
Asked if the Vatican is fishing for African souls, Moynihan is quick to respond: “Of course.”
However, he says John Paul’s legacy points to a new kind of dialogue with Islam:
“There’s a chance to express one’s views, even in the hope of persuading others, without imagining that you have to coerce them in any way," he says. "And you hope that the other partner will also feel the same way. You will listen to their arguments. If their arguments are persuasive, you may even be tempted to believe them. It’s a completely free exchange of views that has a certain dignity. And it prevents violence.”
However, Moynihan adds that Christians increasingly fear that Muslims will rely more on government funding and military means to win over converts -- as opposed to simple persuasion.
That view seems to be common inside the Catholic Church.
Gerald O’Connell is a veteran Vatican watcher and author of “God’s Invisible Hand,” a book about Nigeria’s Cardinal Francis Arinze.
For two decades Arinze, 74, led the Vatican’s office for interfaith dialogue. Moynihan says the black African has a deep respect for Islam. But O’Connell says that Arinze is also known for taking a tough stand against what he sees as the political manipulation of Islam by leaders in some Muslim countries
“He believes that in several majority Muslim countries, including his own Nigeria, that political leaders manipulate the religious factor -- in other words, they manipulate Islam for their own particular purposes and interests," O'Connell says. "And he has told me that he has asked several times religious leaders in the Islamic world, he’s pointed this out to them and asked them to, and hopes that they will take a stance against it.”
Regardless of who is elected pope, the next leader of the world’s one billion Catholics is widely expected to build on the foundations laid by John Paul and seek dialogue with the Muslim world.
But both Moynihan and O’Connell say that the choice of Arinze would be particularly significant in that regard.
If Karol Wojtyla was the Catholic response to the Cold War divide, the Nigerian cardinal could be its answer to the “clash of civilizations.”