COLUMN RIGHT : Use of Force Is What Keeps Cops Alive : In most cases, just having that option is deterrent enough.

The video recording of the brutal beating of a motorist by Los Angeles police officers caused the nation to ask how the police, who are sworn to abide by the law, can behave so violently.

The answers by well-meaning experts generally miss the main point: Police officers have to behave violently. Otherwise they won’t survive, period.

Consider this small calculation. A police officer has to use force in only 1% of the cases in which he is involved. Assume that a serious injury to an officer occurs in 1% of those cases. Assume also that a police officer can recover from two serious injuries in the line of duty, but a third would force him to retire. Of 30,000 cases, only one would end with a police officer out of service. This is a very modest estimate if we take into account the nature of the work and the people with whom the police have to deal.

Assume that an officer encounters 10 citizens in one shift (and this is not unusual). We would have to predict that an average police officer will retire because of medical problems suffered on the job after about 10 years of duty.

Yet this rate of retirement doesn’t happen, and the question is, why? Criminals are rarely pacifists, and police officers are rarely superhuman. The clue to the amazing survival of police officers is simple, if unpleasant: reliance on the use of force.

What behavior will get the maximum reaction from the police? There is almost universal agreement among the public: showing disrespect to an officer. And attacking a police officer can be suicide; a person would have to be certifiably crazy to attack an officer physically, because the perpetrator may not survive.

The public is absolutely right. Research shows that confronting a police officer is the worst strategy in any circumstance. The extent of the injury to the officer, if any, is not relevant. What is relevant is the fact that the person was crazy enough to attack a police officer.

It is not cruelty or excessive pride that makes the police respond with force; it is a means of survival. With this response available to them, the police create a climate in which no one will consider attacking them. Even serious criminals are careful to avoid encounters with the police. If this climate were to disappear, police work would be prohibitively dangerous; no officer would survive for long.

Here we face another unpleasant fact: Force is efficient. People confess, give evidence, cooperate and avoid committing crime because of fear. And fear of an immediate physical reaction by the police is much more effective than an abstract sanction by the court. We did not eliminate force and torture from our law books because they don’t work but because they are unjust and inhuman. However, even an idealistic police officer will learn very quickly that many times he has no choice but to use force.

Moreover, the use of force does not always hurt the guilty. Every police officer knows that in violent demonstrations, those who get kicked the most are not the ones who throw the most stones, but those who run the slowest. If just a few officers have to confront a large, unruly crowd, the only effective strategy is to start beating people until the crowd disperses, otherwise there is a real chance that the crowd will turn into a dangerous mob. A good chief tries to avoid circumstances in which his officers are extremely outnumbered. But when it happens, there is no other choice but to use force.

Unfortunately, a culture of violence has many bad manifestations. When the use of force becomes legitimate, no one can predict exactly where it will stop, and no one can control it. The Rodney King incident is only one example of what can develop from such behavior.

However, anyone who criticizes the police should be prepared to offer viable alternatives--to explain precisely how the police can fulfill their role as crime-fighters without using force. Just complaining about police brutality is neither fair nor constructive.

The public must recognize the reality of crime-fighting and give police officers better and more effective protection in their often thankless work.