This month marks the tenth anniversary of what was at the time the worst terrorist attack ever on American soil.  The bombing of the Alfred P. Murrah Federal Building in Oklahoma City – an attack by a domestic right-wing terrorist, Timothy McVeigh – killed 168 people and injured hundreds more.

Today, in the aftermath of the attacks on 9/11, the threat posed by domestic terrorists has largely faded from the consciousness of many Americans.  However, this threat is still serious, and should not be ignored or overlooked.

True, right-wing extremists in the United States are more disorganized today than they were in 1995.  In recent years, many long-established white supremacist groups have suffered severe disruptions due to the death or incarceration of key leaders such as William Pierce of the National Alliance, Richard Butler of Aryan Nations, and Matt Hale of the Creativity Movement.  These setbacks have made such groups less effective, but have also increased the threat of "lone wolf" activity – criminal actions undertaken by extremists who do not necessarily belong to any organized group.  This phenomenon explains much of the recent rise in racist skinhead violence.  

Another major change has been the way in which the Internet has transformed the extremist world.  Today, extremist groups use it to propagandize, fundraise, recruit, mobilize, and even plan events.  Extremist efforts such as "Project Schoolyard," an attempt by an extremist record label to distribute 100,000 racist hate music CDs to American school children last fall, would not have been possible without the Internet.  The ability of extremists to spread their ideology anonymously over the Internet is perhaps the greatest sea change since 1995.

The potency of this threat was brought into stark relief when Jeff Weise, a 15-year-old high school student, killed nine people and himself in a shooting spree in Minnesota.  Weise was infected with hate, and had found an outlet for his admiration for Hitler on an online neo-Nazi forum.

In recent years, domestic extremists have plotted to kill judges and other government officials, attacked targets ranging from synagogues to abortion clinics, and have even built chemical weapons.  Since the Oklahoma City bombing, 15 law enforcement officers have been killed by white supremacists and anti-government extremists.

In some ways, the domestic threat is actually wider today than it was ten years ago.  In addition to right-wing anti-government and white supremacist groups, other dangerous organizations have emerged.  Left-wing radicals such as animal rights and environmental extremists pose considerable concern today, as do domestic radical Islamists, including some Americans who have trained with or provided material support to Al Qaeda or the Taliban.

Fortunately, law enforcement officials at the federal, state and local level have not been complacent.  In the wake of the 1995 bombing, the law enforcement community learned three key lessons, and these lessons have shaped their counter-terrorism strategies ever since.

The first lesson was an appreciation that state and local law enforcement play a crucial role in combating – and preventing – domestic terrorism.  It was an Oklahoma State Trooper who arrested Timothy McVeigh, not an elite federal counterterrorism squad.  After the bombing, the Justice Department established training programs to help educate state and local law enforcement agencies on domestic terrorism issues.  Many state and local agencies have themselves set up counterterrorism sections or added domestic terrorism to their criminal intelligence responsibilities.

Second, it became readily apparent that communication and cooperation between different law enforcement agencies and jurisdictions is vital.  One key tool that received a significant boost after Oklahoma City was the concept of the "Joint Terrorism Task Force" – multi-jurisdictional task forces that brought agencies together to pool resources and expertise.

The third lesson was that if the goal is to prevent acts of future terrorism, intelligence is critical.  A variety of information-sharing resources and tactics, from working groups to shared databases, have emerged in the past decade – all designed to put key information in the hands of people who can use it proactively to reduce the risk of new terrorist attacks.

These lessons – when taken to heart – have been effective.  In the past decade, numerous acts of domestic terrorism, including bombing conspiracies and assassination plots, have been prevented largely thanks to the law enforcement strategies implemented in the wake of Oklahoma City.

But there is still an undercurrent of extremist activity in this country that demands rigorous scrutiny by law enforcement, watchdog organizations, government agencies and legislators.  Only through continued vigilance and awareness will the United States be able to continue to prevent an attack like the Oklahoma City bombing from being repeated.

The Anti-Defamation League, founded in 1913, is the world's leading organization fighting anti-Semitism through programs and services that counteract hatred, prejudice and bigotry.