The atrocities of September 11 are often said to have begun"a war like no other," but in fact, it is not the first time the United States has faced this kind of terrorism. Long ago, in 1919 and 1920, the nation was terrorized by random bombings, and gripped by the fear that an anarchist conspiracy was set to destroy the American government.

The panic after World War I is a case study in how not to face down a terrorist threat. The security follies back then launched a revolution in civil liberties, which make it nearly impossible for the government to make the same mistakes now. Nevertheless, there are echoes of the current crisis in the earlier threat of anarchist revolution. Like the September 11 terrorists, anarchists demonized the modern capitalist world as the root of all evil, and a few thought revolutionary violence would win the future.

1919-20: The Postal Service, and the Financial District, Under Siege

Bombs, not anthrax, were the postal weapon of choice in the early 20th century. In the spring of 1919, numerous government officials such as Attorney General A. Mitchell Palmer and the venerable Justice Oliver Wendell Holmes, Jr., received bombs. One exploded in Atlanta, and the explosion alerted an observant clerk, who identified 36 more bombs waiting for delivery at a New York post office.

In late 1920, the conspirators made their biggest strike, in New York's financial district at the corner of Broad and Wall Streets. A bomb left in a horse-drawn wagon targeted both government and financial power. Government offices, including a Sub-Treasury office, were on one side of the street. On the other was J.P. Morgan and Company.

Suppressing Radical Dissent, and Detaining Friends and Relatives

Of course, the would-be revolutionaries of 1920 had no more chance of actually destroying their enemy than Osama Bin Laden does now. Nevertheless, the mere thought that a violent revolution might be imminent scared government officials into action.

Led by Attorney General Palmer, the administration stepped up its suppression of radical dissent, deploying the legal tools left over from the war. Radicals such as Emma Goldman and Alexander Berkman had already been deported to Russia for attacking the draft. And now the Sedition Act of 1918 made it illegal to even criticize the war effort. Famed labor leader and early socialist Eugene B. Debs was jailed for doing just that.

To preempt the threat of revolution, Palmer arrested union leaders and Communist Party organizers. Even relatives and friends visiting the arrested radicals in Hartford, Connecticut were jailed as a threat to public safety.

Deportations and Mass Arrests

Most of the alleged plotters were recent immigrants from southern and eastern Europe. They were summarily deported under wartime labor laws (even though the war had ended) that allowed the Labor Secretary to deport anybody whose activities threatened war production.

State and local police seized Communist publications without search warrants. They also arrested over 6,000 people — in a round-up which Palmer promised would avert a great plot he claimed to have uncovered. Public support for Palmer quickly evaporated, though, when the raids only unearthed three pistols and no bombs.

That Was Then, This Is Now

Despite some eerie parallels between then and now, we live in a very different time. In recent weeks we have seen an enormous amount of flag-waving patriotism, but not the same all out drive to purge the country of dangerous radicals and foreigners that was evident during the 1919-20 attacks.

Arab-Americans have been harassed and threatened. Men of Middle Eastern appearance have been forced off planes because their mere presence scared other passengers and crew. This time, however, scapegoating has not become official policy, and elected officials have gone out of their way to repeat the Administration's position that we are fighting terrorism, not Islam.

None of this is to say, however, that Attorney-General John Ashcroft has erred on the side of protecting civil rights. Over 1,000 people are being detained as"material witnesses" or have been arrested. And the federal government has adopted a zero tolerance policy for immigration infractions to make sure that any potential terrorists are caught in the dragnet. Better safe than sorry, seems to be the rationale.

The mass detentions and use of deportation procedures are familiar from the early 20^th Century attacks. But there is a difference: The executive now faces real scrutiny from other branches of government when it demands additional security. For example, the Bush Administration's anti-terrorism legislation, The Patriot Act, was amended in Congress to create more safeguards, and the most controversial provisions will expire with"sunset" amendments rather than remaining on the books forever.

Granted, part of Congress' concern was that unconstitutional laws might ultimately cause terrorists to go free, when courts reversed convictions. But anticipation of what courts might do is far from the whole story. Giving substance to the Bill of Rights has also become an unassailable part of our political culture, and no administration can expect to dispense with free speech or criminal rights as Palmer did.

The Beginning of a Cultural Change: Palmer's Legacy

When did the change happen? Ironically, it was the very post-World War I climate in which Palmer's abuses initially occurred that ultimately sparked the sea-change in American legal and political values.

Palmer's wholesale deportations and exaggerated conspiracy threats killed his hopes of winning the Democratic presidential nomination. By the summer of 1920, the man hailed as the Fighting Quaker was being ridiculed as the Quaking Fighter. His stupidly unconstitutional defense of the Constitution became his legacy.

Over the next four or five decades, contemporary beliefs protecting racial and religious pluralism were gradually built into constitutional law. Justices Holmes and Brandeis planted the seeds in United States v. Abrams. Holmes had approved the Court majority's decision to outlaw antiwar speech in earlier cases, but in Abrams, he wrote that any criticism should pose a real threat to the military effort before it was made a crime. Holmes thought that the ravings of an emigre socialist posed no threat at all

Pacifists no longer seem to threaten the constitutional order. Their critics are more likely to side with Holmes and deride them as pathetic, not dangerous. Now, instead, it is those who advocate violence who concern us — and even their civil liberties are honored.

The legacy of the Warren Court is often attacked as"judicial activism." But now that we are living with its much more active enforcement of civil liberties, our political culture has become much safer for those who might be caught in the terrorist dragnet, including innocents who may have suspected as little as the average citizen did of what might happen on September 11.

Fortunately, because of all these developments, our legal system is much less likely to fall prey to demagogues, or to the tyranny of the majority that accompanied the terrorist threats earlier in our history.

This piece first appeared in Findlaw.com and is reprinted with permision.