According to the FBI, radical environmental groups are the largest and most active domestic terrorist organizations, responsible for $43 million worth of damage since 1996. Such groups have targeted various corporate entities ranging from animal-testing centers to bio-engineered crops and the paper industry.
It remains unclear, however, whether the effort by business groups, some conservatives and congressional interests to tie this problem to the Bush administration's war on international terrorism is appropriate. Such concerns are based upon that fact that groups like the Animal Liberation Front, its sister organization Earth Liberation Front, and Earth First! -- whose primary means of operation are arson, burglary, assault and vandalism -- do not provide the same level of public threat as lethal international terror groups like al Qaida.
Bruce Hoffman, a terrorism expert in the Washington office of policy research organization RAND, told United Press International that though the FBI classifies these groups as terrorist organizations and they represent a real threat, their level of sophistication keeps them from providing the same degree of threat as international groups like al Qaida.
"There are a different type of terrorist groups with differing levels of expertise and different types of terror tactics," said Hoffman. "There is an absolutely different level of sophistication. The ELF and ALF have tended to be non-lethal and less active in the U.S., whereas one could classify al Qaida as homicidal."
He pointed to the fact that some of the agents in the international terrorist organizations that have been targeted in the war on terrorism have been in engaged in actual warfare for more than a decade.
Hoffman added that despite such differences, the separate movements are similar in that they both utilize nonlinear networks and autonomous cells, the worldwide operating model for terror groups.
James Phillips, an international terrorism expert and research fellow at the conservative Heritage Foundation, told UPI that though groups such as the ALF and ELF are not allied with international terrorist groups like al Qaida, they are learning from their more lethal counterparts.
"I would say that there is not necessarily a link to the foreign groups but I think there is a link in the sense that some of these (eco-terrorist) groups are copying tactics of other more established international terror groups," said Phillips.
He noted that even the use of the word "front" in their names by ALF and ELF is designed to provoke, harking back to Marxist terminology.
Despite the differences in the level of terror promoted by the different groups, Hoffman believes it is important to keep in mind that both the environmental and political movements are criminal in nature and should not be treated differently under the law.
"To my mind a crime is a crime," said Hoffman. "To me that is the defining characteristic. That is why we have a nation of laws. You cannot decide which criminal acts you are going to pursue and which you are not."
Some critics believe the inconsistent public view of environmental terrorism versus other forms of terrorism is due to the fact that such groups do not aim their actions to injure or kill people and that the stated mission of groups like ELF and ALF -- to save the planet and the animals -- is one that resonates with many Americans.
But Phillips says their tactics are no different than those of any other individual or group that resorts to violence to make a point, and should be treated accordingly.
"I think any terrorist group should be tracked down and apprehended," said Phillips. "I also think that anyone who bombs an abortion clinic should be tracked down and arrested. In the broader sense you can make the argument that tolerating terrorism on one issue undermines the whole antiterrorism war."
As to whether focusing on this eco-terrorism problem serves to divert attention from the more dangerous issue of groups like al Qaida, Hoffman said that though a balance is needed, the U.S. government cannot choose between which types of terrorism it should fight.
"I think there is a system of priorities," he said. "Those groups which most directly harm Americans and affect the national security of the United States is where out attention is focused. But that is not to say that we shouldn't pay attention to other acts of terrorism."