Historian Andrew Preston first became interested in the overlap between religion and America's foreign policy decisions while teaching an undergraduate class on American foreign policy in the days leading up to the 2003 invasion of Iraq.
"My students took it for granted that [Osama] bin Laden would use extremist rhetoric, [but] they were more surprised by [President George W.] Bush's use of religious imagery and religious rhetoric to explain American foreign policy," Preston tells Fresh Air's Terry Gross. "And they asked me if this was unusual in American history, if presidents turned to religion very often. ... I told them that I'd find out some more. I said that in general, I thought that religion didn't play much of a role in U.S. foreign policy."
But Preston says he wasn't convinced of his own answer. He decided to research the topic further, only to find that historians had largely overlooked the relationship between religion and foreign policy throughout American history.
"And once I started looking at the documents, once I started looking for religion, it was everywhere," he says. "And I thought, 'This would be something I'd like to work on.' "
The result is his book Sword of the Spirit, Shield of Faith, which traces how religious language has been invoked to support U.S. foreign policy decisions throughout the country's history and up to the present day.
Preston explains, among other things, how Abraham Lincoln's use of religious rhetoric during the Civil War helped influence later humanitarian missions, and how religious liberty was a major factor for Franklin Delano Roosevelt when thinking about the U.S. role in World War II.
Even before the country was founded, Preston says, early settlers used their religious doctrines to frame their thinking. The earliest settlers to the New World came looking for a haven from religious prosecution, but also wanted to protect their faith from opponents throughout Europe.
"At various points it looked like it might not survive," he says. "So at various points, the [early settlers] wanted to bring the Protestant faith to the New World to keep it safe and let it grow."
The Puritans ended up identifying the protection of their Protestant faith with their own physical security, he says.
"They believed that not only did they have to protect that idea to protect themselves, but they believed that they had to spread it," he says. "And by spreading that idea, they would ensure its survival, ensure its prosperity, and then they would ensure their own survival. And this kind of exceptionalism has been fairly constant and continuous in American history."
Preston points to the charter of the Massachusetts Bay Colony — the group that would found the state of Massachusetts, which clearly states that its primary goal was to "incite the natives to the knowledge and obedience to the only true God and savior of mankind."
"They had some strong ideas about their own faith and their own virtue and the virtue of their own faith," he says. "These people who founded Massachusetts, they were seeking religious liberty and they were complaining about the persecutions they suffered in England. And of course, the first thing they do when they get to Massachusetts is persecute others and persecute their religion."
Since its founding, Preston says, America has seen itself as "God's chosen nation."
"It is a very powerful strand," he says. "Part of it comes from the Protestant faith that some of the first colonists brought over with them: a Calvinistic belief in providence that God had a plan for people, that God had chosen people and that Americans were one of those peoples — they were God's instrument on Earth to do good and to rid the world of evil."
Preston says he thinks this belief still exists in the country today.
"I think a lot of Americans believe that, and I think it provides a very strong motivation for people calling for America to act the way it does in the world," he says. "You can see it in the rhetoric around quite a few wars. You could see it in the rhetoric in George W. Bush's language in justifying the war in Iraq. Whether that decision was right or wrong ... I don't take a stand on that, but that sort of idea — that America is chosen ... was all over Bush's rhetoric. But Bush was certainly not an aberration in American history. He was actually quite typical."
On religion providing some of the core ideas for the founders of the United States
"Even people like Thomas Jefferson or George Washington, who weren't very religious ... saw religion as the source of conscious morality, and therefore you had to protect religion almost at all costs. And Thomas Jefferson ... who certainly didn't have any faith in the divinity of Christ, even he believed that you had to protect individual conscience and therefore you had to protect religion. But in order to protect that, and to prevent ecclesiastical tyranny, you had to separate church and state — and that's where these early ideas emerged."
On the separation of church and state
"The First Amendment has the free exercise clause and the establishment clause, and that's pretty much it. And how that was interpreted for the first 150 years was that religion had a role in public life, religion had a role in politics. It just meant that the government couldn't regulate religion; it couldn't set up a national church, and it couldn't interfere with the way people worshipped. Essentially what it did was make Protestantism the unofficial religion. That only changed after World War II, when our nation became more religiously pluralistic and other groups like Catholics and Jews started challenging the Protestant domination. The Supreme Court decided to make things more simple for a modern era by hardening what Jefferson called the 'wall of separation between church and state.' The best thing to do was to try and remove religion from public life as best as people could."
On FDR and foreign policy
"FDR by 1937 wanted the United States to play a more active role in world affairs and a much more active role in resisting Nazis – maybe not to go to war, but certainly to take a more active role in resisting Nazism. And he constantly evoked both 'the sword of the spirit' and the 'shield of faith' in overtly religious language – speaking of religion by name and quoting from the Bible, and especially pointing to the threat the Nazis posed to all religions. And he used the 'sword of the spirit' to call for a robust American foreign policy. But he also used the shield of faith to couch it in terms that were very much about implementing world peace and spreading democracy."
On American exceptionalism
"To most people it means that America is exceptional in that it's not only different, but it's better. And often it's better because of those differences. And America is a unique force of good in the world, a unique force for virtue. And exceptionalism usually applies to people who believe that America should spread this virtue or should share it in the rest of the rest of the world, and often that results in conflict and/or war."
TERRY GROSS, HOST:
This is FRESH AIR. I'm Terry Gross. Religion continues to play a big part in American politics, and much has been written about that. Far less has been written about the role religion has played in the history of American foreign policy, either in justifying war or avoiding it.
My guest, Andrew Preston, decided to write a book on this subject several years ago, when he and his students were discussing President Bush's use of religious imagery in justifying the war in Iraq, and he found his students were puzzled by the presence of religion in the normally hard-headed world of diplomacy, especially American diplomacy.
Preston teaches American history and international relations at Cambridge University, and before that, taught at Yale. His new book is called "Sword of the Spirit, Shield of Faith: Religion in American War and Diplomacy." Andrew Preston, welcome to FRESH AIR. Let's go back to the colonial era.
Settlers came here from England, early on, looking for religious freedom because they were persecuted in England.
ANDREW PRESTON: That's right.
GROSS: But when they came here, what were some of the religious goals that they had?
PRESTON: Well, first and foremost, they wanted a haven. They wanted safety from religious persecution. But more importantly for my purposes, certainly for the book, what they also wanted to do was protect the Protestant faith because it was under siege all over Europe, and it was under siege in England, not just - England was going through a lot of very intense religious politics.
Those would play out in the English civil war. Europe ended up fighting for centuries over questions of religion, and at various points, Protestantism looked like it might not survive. And so one of the things that they wanted to do was bring the Protestant faith to what they called the New World in order to keep it safe, in order to let it grow.
And because of that, they ended up identifying the protection of an idea, of a religion, of the Protestant faith, with their own physical security - and that one and the two were the same. And also they believed in the converse, that not only did they have to protect that idea and protecting that idea would protect themselves, they also had to spread it. And by spreading that idea, they would ensure its survival, they would ensure its prosperity, and they would ensure their own survival.
And this kind of exceptionalism, I think, has been fairly constant and fairly continuous in American history.
GROSS: You quote the founding charter of the Massachusetts Bay Company, this is the group that founded Massachusetts, and the founding charter stated that its primary goals included to incite the natives to the knowledge and obedience of the only true God and savior of mankind.
And then the official seal of the Massachusetts Bay Colony pictured an Indian pleading: Come over and help us.
PRESTON: That's right.
GROSS: Boy, when I read that, I thought, wow, they were really delusional.
PRESTON: They had some pretty strong ideas. They had some pretty strong ideas about their own faith and their own virtue, and the virtue of their own faith. So these people who founded Massachusetts, they were seeking religious liberty, and they were complaining about the persecutions they suffered in England. And of course, the first thing they do when they get to Massachusetts is persecute others and persecute their religions.
So it's not an easy story. It's not always a comfortable story. It can be fairly contradictory at times. But I think that's what makes it even more interesting.
GROSS: So, so many settlers in the colonies were Protestants from England. How did religion come into play in the justification of the Revolutionary War, which was going to be fought against fellow Protestants?
PRESTON: That's a great question, and historians still argue a lot about religion and the American Revolution. I argue in the book that religion provided some of the core ideas for a lot of the people who would become founders and certainly the people who fought against British rule.
Even those people like Thomas Jefferson or George Washington, who either weren't very religious or had a very personal, very eccentric - and I mean that in the best way, I don't mean that as an insult - but a very eccentric faith, a very eclectic faith. They saw religion as the source of conscience, they saw religion as the source of morality, and therefore you had to protect religion almost at all costs.
And Thomas Jefferson, who we know wasn't - he was a cultural Christian, I guess is what we'd call him, a cultural Protestant, because he certainly didn't have any faith in the divinity of Christ or anything like that. Even Thomas Jefferson believed that, that you had to protect individual conscience, and therefore you had to protect religion. In order to protect that, but also in order to prevent ecclesiastical tyranny, you had to separate church and state. And that's where these early ideas about the separation of church and state emerged.
GROSS: How do you think the idea of separation of church and state has evolved over time?
PRESTON: It's evolved in really interesting ways, in ways in which a lot of Americans I think would be surprised, given the state of politics over the separation of church and state today. For most of American history, the separation of church and state favored the church.
The First Amendment has the free exercise clause and the establishment clause, and that's pretty much it. That's all it says. And how that was interpreted for the first 150 years, at least, of the nation's history, was that religion had a role in public life, religion had a role in politics. It just meant that the government couldn't regulate religion; it couldn't set up a national church, and it couldn't interfere with the way people worshipped.
And effectively what that mean, because America was so overwhelmingly Protestant, was that it gave - it effectively made Protestantism the unofficial religion. And that began to change after World War II, as the nation became more religiously pluralistic and as other groups like Jehovah's Witnesses and Catholics and Jews and Mormons became more confident and started challenging this Protestant domination.
The court decided just to make things simpler for a modern era by hardening what Jefferson called the wall of separation between church and state. And so, the best thing to do was to just remove religion from - or at least try to remove religion from public life as best as people could.
GROSS: So in talking about how America became a more pluralistic, ecumenical country, you describe President Franklin Roosevelt as being the first president to really see the United States as a Judeo-Christian country - Christian in terms of being inclusive of different Christian denominations and faiths and Judeo in terms of including Jews in that, too.
PRESTON: That's right.
GROSS: So how did that come into play in his thinking? And I should say, I don't know if he actually used the word Judeo-Christian or not, but you say that that's the way he saw the United States.
PRESTON: Absolutely. This is definitely how he saw the United States, and I think it came, really, from two sources. One was just his own personality, and I don't think historians have done enough work on FDR's own personal faith. And his religious background, his religious philosophy was he was very religious but in a very informal way, in a very inclusive way. He believed...
GROSS: He was Episcopalian, right?
PRESTON: He was an Episcopalian, and he came from a tradition in the church - he was raised in a tradition of the church - he was obviously from a very well-to-do background, but he very strongly believed in, you know, a tradition of noblesse oblige, of giving back to society, of public service.
He also didn't have much time for theology, which is also a very strong tradition in - among certain Episcopalians. And because of that, he instinctively had an ecumenical outlook. But then also because he became a politician in New York, especially a Democratic politician, Democratic Party politician in New York, even if he wasn't naturally ecumenical or interfaith, he had to include Jews and Catholics, otherwise he wouldn't have been elected.
And so these two formative influences, his own personal background and faith and then his political milieu, really pushed him to be very inclusive and very ecumenical. And that's the world view, that's the vision that he used to explain the world crisis in the late 1930s and early 1940s.
GROSS: What do you mean?
PRESTON: The late 1930s and '40s were a time when most Americans didn't want to get involved in the world crisis that was emerging. They didn't want to get in European affairs. They didn't want to get involved in Asian affairs, and you can understand why.
They were living through the Depression. The reasons for intervening in World War I and Wilsonianism had been discredited by then. But FDR himself was convinced that the United States had to do more because this was a very serious threat.
And so beginning in 1936, 1937, when again, most Americans were absolutely opposed to getting involved more in Europe and Asia - and at a time also when there was no way that Germany or Japan were going to attack the United States, the continental United States, that just wasn't even a possibility, and that was the most effective argument that isolationists had. FDR started describing the threat from Germany and Japan, and especially from Germany, as a threat to religion, not just to the Jews, although he did emphasize that, but to all people of all religion.
And he said this was a problem because religion - just like Thomas Jefferson and George Washington and James Madison argued in the 18th century - FDR argued that religion was the source of democracy because it was the source of conscience and morality. And because religion was the source of democracy, democracy was also the source of international peace. You couldn't have international peace without democratic countries.
And so everything rested on religion, and he said this in his 1939 State of the Union address. And so for him, it was good foreign policy to emphasize the Nazi threat to all religion but then also to offer the alternative, which was America's - as he couched it, America's Judeo-Christian traditions, its heritage of religious tolerance, of pluralism in which the separation of church and state prevented the government from meddling with religion as it was doing in Germany and the Soviet Union and elsewhere and that religion could be free in the United States, and that's why the United States was democratic.
GROSS: And in doing that, did he ever quote the Bible, like say George W. Bush did, or talk about his own personal faith?
PRESTON: All the time. Yeah, he did that quite often. He would quote from the Bible. He would paraphrase from the Bible. He would talk about his own faith. FDR was a master at personal politics and at personalizing things in a very comforting way. And he did that all the time, and then to bring the message home, he would argue, and he would tell Americans that - he didn't use the term - but he would say in a globalized world, America cannot remain a lone island in a world dominated by force. It can't be the only democracy, it can't be the only religious country in a world that's been conquered by the forces of atheism and tyranny, because eventually - it might take a long time - but eventually those threats will harm America.
GROSS: I never saw the Nazis as atheists. I saw them as believing in their own kind of mono-culture that included their religion.
PRESTON: Yeah, that's true. It depends on which Nazis you're looking at, but no, that's absolutely right. And actually, I should say that FDR didn't couch the Nazis as atheists. He would say that they were pagans, that they wanted to set up their own cult around the worship of Nazism, where, as he said, "Mein Kampf" would replace the Bible, and the swastika would replace the cross.
It was a threat to religion all the same, and this is an era, of course, where there was lots of atheism around in Europe and especially in the Soviet Union.
GROSS: So in talking about how FDR used religion to help rally people to go to war against the Nazis and against Japan, how much of this do you think was just knowledge of how to change popular sentiment away from non-interventionism toward, you know, going to war; and how much of it do you think was genuine personal belief?
PRESTON: Yeah, that's one of the riddles that is impossible to answer, definitively, one way or the other. I myself am completely convinced that FDR did it for both reasons, that it was consistent with his own private beliefs - that what he was saying was consistent with his own private beliefs - that he was - that these private beliefs gave him ideas about the wider world and how to interpret that wider world.
But clearly it was good politics. Using religion to explain to a country that was very religious, the United States - and still is, of course - was an easy way to describe the threat, to explain the threat that after all probably wasn't going to come in the form of a bomber or a tank - unless, as Americans found out in 1941, unless you were living in Hawaii.
But if you were in the continental United States, you weren't going to be attacked. So religion provided a very - not the only reason, or not the only justification - but it provided a very compelling reason why Americans should get more involved in the world.
GROSS: If you're just joining us, my guest is Andrew Preston, and he's a professor at Cambridge University. His new book is called "Sword of the Spirit, Shield of Faith: Religion in American War and Diplomacy." Let's take a short break here, and then we'll talk some more. This is FRESH AIR.
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GROSS: If you're just joining us, my guest is Andrew Preston. He's the author of the book "Sword of the Spirit, Shield of Faith." It's about how religion has figured into American war and diplomacy.
So you've said that the idea of American exceptionalism really dates back to the colonial era, to our earliest history in the United States.
GROSS: What does the idea of American exceptionalism actually mean?
PRESTON: Well, to most people, it means that America is exceptional in that it's not only different but that it's better. And often it's better because of those differences. But that America is a unique force of good in the world, a unique force for virtue. And exceptionalism mean, usually means that - it usually applies to people who believe that America should spread this virtue or should share it with the rest of the world, and often that sometimes results in conflict and in war.
GROSS: And what are some of the things American exceptionalism has been used to justify over the years?
PRESTON: Well, in pretty much any war or any major crisis, you'll find exceptionalist rhetoric about the virtue of America and benevolence of America. It could be Lincoln speaking of America as humankind's last best hope. It could be FDR saying that the United States can't be an island of democracy in a world governed by force. It could be any kind of rhetoric like that, sort of positioning America as a unique force for good in the world.
GROSS: And is religion always seen as an inherent part of American exceptionalism?
PRESTON: It usually is. Almost all commentators on religion and American politics, and especially the few people who have looked at religion and American foreign policy, see it as automatically, inherently exceptionalist - that it's always exceptionalist. And religion certainly has been a major source of American exceptionalism, there's no doubt about that.
GROSS: In what ways?
PRESTON: In providing ideas about why, about how America is different and how America is better than other countries. And it's also, sort of, provided evidence for others to see America as exceptional, not necessarily better, but also different. So for instance, Europeans always looked - increasingly secular Europeans, rather - over the last 40 or 50 years, looked to the United States as an exception because as society has got more modern, the thinking went they would automatically become more secular, and the United States was the most modern society in the world, and it was becoming more religious.
And so Europeans would always say, you know, would speak of American exceptionalism in that way. But for Americans, religious ideas, religious imagery, especially the notion that America is God's chosen nation, is a very powerful strand in American exceptionalism.
GROSS: How is America first seen as God's chosen nation? Like what did that mean?
PRESTON: Part of it comes from the particular kind of Protestant faith that the first - some of the first colonists and a lot of succeeding waves of colonists and immigrants - brought over with them. A Calvinistic belief in providence, that God had a plan for people, that God had chosen peoples and that Americans were one of those chosen peoples.
And by the modern period, by this period, that Americans were God's chosen people. They were God's instrument on Earth, to do good and to rid the world of evil.
GROSS: Do you think there are a lot of Americans who still believe that Americans are God's chosen people?
PRESTON: I do. I think a lot of Americans believe that, and I think it still provides a very strong motivation for people calling for America to act the way it does in the world.
GROSS: The evidence is? An example?
PRESTON: Well, you can see it in the rhetoric around quite a few wars. You could see it in the rhetoric in George W. Bush's language in justifying war in Iraq. Whether that decision was the right decision, whether it was the wrong decision, I don't take a stand on that in the book, but that sort of idea that America is chosen to - and that language that Bush used, explicitly, that America's been chosen by God to spread certain values and to protect certain values. It was all over Bush's rhetoric before the Iraq war.
But it certainly isn't unique to Bush. Bush is absolutely not - was not an aberration in American history. He was actually quite typical.
GROSS: So a lot of people who fled their countries and fled to the United States, came here in full or in part, because of religious persecution. And how do you think that's affected the religious identity of the United States?
PRESTON: Well, that's the source of America's religious pluralism. It's - it has been for a long time the most religiously pluralistic society on Earth, and I don't think that could've happened, that wouldn't have been possible without successive, as you said, successive waves of immigration from various parts of the world - first Europe, and then other parts of the world - happening over centuries and that are still happening right up to the present.
One thing that immigrants from religious communities - Catholics, Jews, Muslims, Buddhists, Hindus, more recently - have done is pay a lot of attention to what's happening to their co-religionists back home or in other parts of the world, not necessarily where they came from.
And they have formed very effective, I guess we'd call pressure groups, in lobbying or trying to influence the American government to taking a particular - to advancing a particular cause or to push the cause of human rights for a certain group. We saw this a lot with Catholics in the 19th century. We saw it a lot with Jews in the late 19th century, after Russian pogroms and Romania's brutal repression of its Jewish population in the late 19th, early 20th century. So it's certainly not a new phenomenon. And that's what religious immigrant communities bring to American foreign policy.
GROSS: Well, Andrew Preston, I want to thank you so much for talking with us.
PRESTON: Oh thanks, Terry, it's been a pleasure.
GROSS: Andrew Preston is the author of the new book "Sword of the Spirit, Shield of Faith: Religion in American War and Diplomacy." You can read an excerpt on our website, freshair.npr.org. I'm Terry Gross, and this is FRESH AIR. Transcript provided by NPR, Copyright National Public Radio.