A country’s greatness can be measured by its power to intimidate and its ability to inspire.

The two can reinforce each other, but they can also work at cross purposes. Inspiration takes time and has a general effect, whereas intimidation can work quickly and have a precise impact. Consequently, there is a temptation to rely on intimidation too much, thereby creating resentment. Over time, this resentment erodes the ability to inspire.

The United States was created in an act of rebellion against empire. Its greatness, which the Founders foresaw, was to be based on its inspiring ideals. As George Washington put it in his Farewell Address, “it will be worthy of a free, enlightened, and at no distant period, a great nation, to give to mankind the magnanimous and too novel example of a people always guided by an exalted justice and benevolence.”

We still retain the ability to inspire, even though we have not always been such a shining example as Washington envisioned. Anyone who doubts this should visit college campuses and marvel at the number of foreign students who still see the United States as a place of opportunity, a ticket to a better future.

The foundation of American idealism is its embrace of diversity. At the dawn of the modern era, with the identification of the nation with the state, diversity was considered threatening, something to be avoided and even violently suppressed. The path to national greatness was a uniformity based on “one king, one faith, one law.” The result was decades of bloody conflict. Tolerance emerged out of exhaustion with this slaughter, but diversity was still seen as a necessary evil. The majority tolerated minorities, but did not welcome their presence.

The United States was founded on a different motto: E pluribus Unum. Out of many, One. Diversity was therefore seen as eminently desirable. Uniformity is stifling; sameness provides no room for growth. The encounter with difference provides an opportunity for learning and hence for improvement. The whole becomes greater than the sum of its parts because of this desire for improvement. The United States was settled largely by people who came here looking for something better. Mindful of the past, they were focused on the future, for themselves and their descendants. This focus is essential for progress. A society that is satisfied is a society that will stagnate; a society that defines its identity by its history, and especially by its grievances, will have difficulty responding to new challenges. Societies move forward by cultivating a culture of exploration, the search for something new, which means they must ultimately cultivate a culture of questioning authority. That, of course, was the culture of our Founders, who questioned the authority of King and Parliament. In place of the divine right of kings, they maintained that governments were established to protect the divine rights of the people. In place of obedience, they challenged the power of the government, appealing to “the laws of nature and of nature’s God.”

This language is rooted in the Enlightenment. It represents the emerging spirit of scientific inquiry, designed to uncover the mysteries of nature. Scientific method is based on challenge and response, theory and experiment. Rigorous testing is its hallmark; our knowledge is always conjectural, never final. No matter how good a theory is, we know there is always room for improvement.

Scientific progress rests on this culture of questioning, which helps explain why democracies emerged as the leaders in the field. Authoritarian systems can throw resources at scientific programs, which might provide short-term success. But in the long run, they fall behind, because they lack the proper culture to maintain innovation. This is a major reason why the United States outpaced the Soviet Union in the Cold War.

Unfortunately, our triumph in the Cold War was viewed as a victory for our power, and consequently we thought the application of that power in other parts of the world would yield similarly positive results, but that was not the case. Intimidation does not seem to be working, leaving us with the choice of escalation or retreat.

But there is another way. We can choose to emphasize our ideals. To do that, we must first focus on what we want our country to be, and we must commit ourselves to fulfilling that vision. We must constantly earn our place as “the city on the hill.” That is our challenge, and in that lies our greatness.