"There has never been a successful attack"
This refrain is heard often from those who feel the attention to liquid explosives is somewhat redundant. Critics point to the fact that Richard Reid's shoe bomb failed and other plots were apprehended before they could be executed.
However, we know that terrorists will continue to use a modus operandi, adapting it if necessary, to accomplish their goals.
Given this situation, what can law enforcement do?
Security Solutions International (SSI) trainings emphasize the point that terrorists are constantly adapting in this asymmetrical conflict. By looking for the bomber and not the bomb, we will automatically detect their constantly changing arsenal of weapons.
Without such an approach we are constantly at the disadvantage of the organized force trying to combat a guerilla tactic approach. Terrorist groups were nearly successful with liquid explosives in 1995. Despite this, for more than 10 years and certainly for 5 years after 9/11, there has been no significant effort to stop liquid explosives.
Only in a reactive mode, after August 10, did the TSA institute controls on liquids brought aboard planes. Likewise, the shoe bomber Richard Reid, has caused each and everyone to remove his shoes. But before his ill-fated attempt, noone had to have their shoes checked. This means he could have succeeded if the bomb had not failed.
Terror groups are already designing new improvised weapons of destruction. Since we do not know what these are, they are impossible to detect. The next generation may be a simple aerosol that causes everyone in the plane to be neutralized and allow terrorists to take over the plane. We can not know what weapon they will choose.
However, we can know who they are if we use forms of behavior profiling that will lead us to couriers of destruction. They may even be innocent of the fact they are carrying out a terrorist's agenda — by the simple expedient of questioning such as is practiced in Israeli security systems and comparing answers and body languages to the principles of behavioral profiling. Unfortunately, this has become embroiled in the human rights aspect of ethic and racial profiling — neither of which can be effective per se against terrorists. Just as they change their weapons, terrorist groups change their looks and their members' racial and ethnic identities.
The best defense against any terror threat, liquid explosives included, is prevention and that lies with finding terrorists before they can use their constantly changing arsenals of destruction.