Most Americans have forgotten how repressive a period World War I was. “You can’t even collect your thoughts without getting arrested for unlawful assemblage,” quipped the writer Max Eastman. “They give you ninety days for quoting the Declaration of Independence, six months for quoting the Bible.” Walter Lippmann said Woodrow Wilson’s administration had “done more to endanger fundamental American liberties than any group of men for a hundred years.”

Which makes it all the more remarkable that Lippmann had championed America’s entrance into the war on the grounds that it would further liberal ideals. While fighting for democracy in Europe, he declared, “we shall stand committed as never before to the realization of democracy in America ... we shall turn with fresh interest to our own tyrannies—to our Colorado mines, our autocratic steel industries, our sweatshops and our slums.” The progressive philosopher John Dewey thought the war would unleash a new spirit of public-mindedness in the United States and a “more conscious and extensive use of science for communal purposes.”

It’s easy to deride Lippmann and Dewey for their naïveté. But they’re in good company. Every time America launches a major war, intellectuals predict it will spawn a new culture of public spiritedness and political reform. In 1960, when John F. Kennedy promised to seize the initiative against communism in the developing world—Vietnam would become the test case—sympathetic intellectuals claimed the effort would energize America at home. “This is the challenge of the 1960s: the reorganization of American values,” wrote the historian and Kennedy confidante Arthur Schlesinger Jr. “If we are going to hold our own against communism in the world ... the production of consumer goods will have to be made subordinate to some larger national purpose.”

It was the same after 9/11. For conservative hawks, the “war on terror” offered the chance to replace the tawdry materialism of the 1990s with a devotion to higher things. The “commercial life seems less important than public life,” wrote David Brooks. “When life or death fighting is going on, it’s hard to think of Bill Gates or Jack Welch as particularly heroic.” Liberal hawks (myself included) followed in Lippmann’s footsteps and proclaimed the struggle for democracy abroad an opportunity to revitalize democracy at home. In his edited volume The Fight Is for Democracy, George Packer expressed his hope that the September 11 “attacks and the response would puncture a bloated era in American history and mark the start of a different, more attractive era. I thought that without some such change we would not be able to win this new war—that the crisis that mattered most was internal.”

To some degree, the cultural change that Lippmann, Schlesinger, and Brooks hoped war would bring did indeed occur. Wars do breed social solidarity (at least until they sour) and they spark a new interest in public affairs. At times, the struggle against foreign enemies can even help the oppressed at home, as when African Americans proved their courage and patriotism on the battlefield in World War II and thus laid the ground for an assault on segregation. A few years ago, Glenn Beck created the “9/12 project,” in order “to bring us all back to the place we were on September 12, 2001” when “we were united as Americans, standing together to protect the values and principles of the greatest nation ever created.”