Democracy, of all political systems, stands in the greatest need of an education that produces patriotism.

Many have been the attacks on patriotism for intolerance, arrogance, and bellicosity, but that is to equate it with its bloated distortion, chauvinism. My favourite dictionary defines the latter as ‘militant and boastful devotion to and glorification of one’s country’, but defines a patriot as ‘one who loves, supports, and defends his country’.

Assaults on patriotism are thus failures of character. They are made by privileged people who enjoy the full benefits offered by the country they deride and detest, but who lack the basic decency to pay it the allegiance and respect that honour demands.

Every country requires a high degree of cooperation and unity among its citizens if it is to achieve the internal harmony that every good society requires.

Most countries have relied on the common ancestry and traditions of their people as the basis of their unity. Yet we are an enormously diverse and varied people. The great strengths provided by this diversity are matched by great dangers.

We are always vulnerable to divisions among us that can be exploited to set one group against another and destroy the unity and harmony that have allowed us to flourish.

We live in a time when civic devotion has been undermined and national unity is under attack. The idea of a common culture, enriched by the diverse elements that compose it but available equally to all, is under assault, and attempts are made to replace it with narrower and politically divisive programmes that are certain to set one group against another.

The answer to these problems and our only hope for the future must lie in education. We look to education to solve the pressing current problems of our economic and technological competition with other nations, but we must not neglect the inescapable political, and ethical, effects of education.

If we encourage separatism, we will get separation and the terrible conflict in society it will bring. If we encourage rampant individualism to trample on the need for a community and common citizenship, if we ignore civic education, the forging of a single people, the building of legitimate patriotism, we will have selfish individuals, heedless of the needs of others, the war of all against all, the reluctance to work toward the common good and to defend our country when defence is needed.

Civic sense can come only from a common educational effort. In telling the story of our political experience, we must insist on the honest search for truth; we must permit no comfortable self-deception or evasion, no seeking of scapegoats. The story of this country’s vision and of its struggle to achieve it need not fear the most thorough examination and can proudly stand comparison with that of any other land.

In the long and deadly battle against those who hate our ideals, and hate us in particular, we must be powerfully armed, morally as well as materially. To sustain us through the worst times we need courage and unity, and these must rest on a justified and informed patriotism.

This article was adapted from an essay published in the Wall Street Journal on 27 September 2014.

The author is emeritus professor of history at Yale University.