If you saw the movie “Amistad,” you may think of John Quincy Adams as the genial, idealistic old lawyer Anthony Hopkins played. In fact, Adams was one of the most profound statesmen America ever produced. Adams served one term as president, and had a long career in Congress, but his greatest successes came in diplomacy and foreign policy.

Long before Samuel Huntington, Adams understood our modern “clash of civilizations.” Adams believed that history had set the liberal West on a collision course with the Islamic East. In Adams’s day, as in ours, many sophisticated Europeans thought that the two civilizations ought to compromise their differences in the name of peace. Unfortunately, Adams found, compromise was not always possible. As then constituted, Islamic civilization would not accept Western notions of liberty, equality, and progress, and for that reason the West had to fight to defend both its principles and its interests.

Adams observed the first chapter of this conflict in the 1820s, when the Greeks revolted against their Turkish masters. Embracing the ideals that inspired the Americans in 1776, the Greeks asserted their right to assume an equal station among the nations of the earth. Most European statesmen, still smarting from the French Revolution and the wars that came with it, were indifferent if not hostile to the Greek cause. The Ottoman Empire, which extended deep into the Balkans (controlling all or most of modern-day Greece, Bulgaria, Serbia, and Romania) was an important part of the European balance of power, and they were loath to see it weakened. That young Romantics like Byron fought and died on behalf of the Greeks only reinforced their belief that serious statesmen must be on the other side. Adams disagreed. Greece was important in itself, but it also carried immense symbolic weight as “the birth-place of moral philosophy, and of high souled freedom.” Moreover, Adams realized that the Greek independence movement was the first battle in what would be a long conflict between Islam and the West.

After reflecting upon the conflict, Adams grew concerned that it was serious and feared that almost none of his contemporaries understood it. He thought the matter was of such importance that he wrote a lengthy essay on the subject shortly after he left the presidency in 1829. In this essay, which has become so obscure that even many Adams specialists don’t know about it, Adams set the conflict between the Greeks and the Ottoman masters in the context of the larger course of history. He described the origins of the conflict between Islam and the West, and discussed what was at stake in the conflict.

According to Adams, the key element of the renewed conflict between Islam and the West was that liberalism, the dominant idea in the West, did not even exist in Islamic lands. The reason why the new conflict between Europeans and Muslims was different than previous conflicts was that the modern West’s liberty brought with it the technological and social capabilities that made global communication and commerce possible. Modern Western man, Adams declared in an essay he wrote in 1822, “stimulated by all the wants, and aided by all the energies of civilization, proceeds from art to science, and heaps invention upon discovery, till [ships] . . . bear the productions of every habitable spot upon the globe to every other.” Technological progress shrank the world, making the isolation of Islam from the West impossible to maintain.

Modern technology put Western Europe in a position to dominate Islamic lands. Whereas Christians and Muslims had once been closely matched on the field of battle, it had ceased to be a fair fight. “In the brutal and foul contest of arms, the man of Mahomet was no longer a match for the Christian man.” Adams noted that, with the help of modern weaponry, “a company of London merchants, under the patronage, though with little aid, of their government, [has] subdued in the far more distant regions of Hindustan…millions of the disciples of Mahomet.” Moreover, the desire for increased trade meant that the West could not stand aside. It would penetrate Islamic lands; the only question was what would the effects be, and what could the West do to make them as peaceful as possible.

Europe’s indifference to the fate of the Greeks shocked Adams, just as Europe’s moral obtuseness in the Middle East shocks many of us today. Adams criticized “the more than stoical apathy with which they regard the cause, for which the Greeks are contending; the more than epicurean indifference with which they witness the martyrdom of a whole people, perishing in the recovery of their religion and liberty.” Adams complained that Metternich and other European leaders thought too narrowly about the war, “seeing in the Greeks only revolted subjects against a lawful sovereign.” Much more was at stake, Adams claimed. Europe’s statesmen misunderstood the conflict between Greece and the Ottomans because they thought that Islam was a religion like all the others they knew: they expected Muslims to compromise their beliefs in the interest of peace.

Adams feared that Western statesmen failed to appreciate the Christian roots and context of liberalism. In America and increasingly in Europe, religious freedom had found fertile soil in the Christian notion that religion is primarily about belief and only secondarily about action. Hence, people could be left free to think whatever they wanted so long as they submitted peacefully to the laws. Islam is different; it is fundamentally about law, not about belief. The wish of Islam is that the whole world follow the Law of the Koran. Finding a genuine idea of toleration in a religion that is about law and wants to be universal would not be easy, Adams argued.

The Ottomans understood the fundamental nature of their conflict with the West better than did the statesmen in London and Paris. Adams quoted the Sultan as saying: “this is not like former contests, a political war for provinces and frontiers. …This war must be considered purely a religious war and a national war.” The Sultan called for all Muslims to fight the infidels wherever they found them because the West and Islam had squared off in a battle for domination and survival. Adams feared the Sultan was correct. “In comparison with these considerations [about the great conflict between Islam and the West],” he wrote, “the question of the operation of these events upon the balance of power in Europe is but the dust of that balance.”

In the event Russia came to the Greeks’ aid; and fearing Russian success in 1827, France and Great Britain joined the czar in helping to defeat the Turks. Eventually the great powers recognized a small, independent Greek state.

In Adams’s day, unlike our own, the U.S. had little power to influence events so far from home. While he was Secretary of State in the early 1820s, Adams had campaigned against even token American support for the Greeks. Adams was the architect of the Monroe Doctrine, warning Europe to stay out of the Americas, and indicating in return that the U.S. would stay out of Europe. In light of that policy, America could hardly take an active role in a European conflict. But Adams did not think the same rules would apply forever.

Pat Buchanan and other present-day isolationists are fond of quoting Adams’s July 4, 1821, oration. Regarding the Greek independence movement, Adams said that America “goes not abroad in search of monsters to destroy. She is the well-wisher to the freedom and independence of all. She is the champion and vindicator only of her own.” That was not his last word on the subject, however. In the mid-1820s, President Adams wanted to help the nascent South American republics.

Though Adams thought America in his day should stay out of international struggles beyond the Western Hemisphere, he didn’t think that would always be the case. President Washington had said that Americans should have “as little political connection as possible” with Europe. As his diplomatic dispatches from Europe in the 1790s make clear, Adams agreed. Yet President Adams argued in 1826 that Washington gave counsel for his day, not for eternity: “I cannot overlook the reflection that the counsel of Washington in that instance, like all the counsels of wisdom, was founded upon the circumstances in which our country and the world around us were situated at the time when it was given…. [But] compare our situation and the circumstances of that time with those of the present day, and what, from the very words of Washington then, would be his counsels to his countrymen now?” As the nation grew politically, economically, and geographically, its role in the world would necessarily change.

As the liberal West squared off against the Islamic East, Adams realized that the key question was not whether the modern West would fundamentally alter Islamic civilization, but how it would do so. A century and three quarters later, the question still stands. Liberalism rose in the West on a Christian foundation. But the situation may not be hopeless. Perhaps Islam and the West may find common ground in the idea that all the Abrahamic faiths share, that God created all of us in his image, and for that reason no man is born a slave. On that foundation, perhaps, we can find a principled ground for accommodation and peace between the liberal West and the House of Islam. Adams, who ended his career trying to remind his own countrymen of the importance of those great principles, hoped that would be the case.