Years ago in America, it was customary for families to leave their doors unlocked, day and night. In this essay, Greene regrets that people can no longer trust each other and have to resort to elaborate security systems to protect themselves and their possessions.

1. In the house where I grew up, it was our custom to leave the front door on the latch at night. I don't know if that was a local term or if it is universal; "on the latch" meant the door was closed but not locked. None of us carried keys; the last one in for the evening would close up, and that was it.

2. Those days are over. In rural areas as well as in cities, doors do not stay unlocked, even for part of an evening.

3. Suburbs and country areas are, in many ways, even more vulnerable than well-patroled urban streets. Statistics show the crime rate rising more dramatically in those allegedly tranquil areas than in cities. At any rate, the era of leaving the front door on the latch is over.

4. It has been replaced by dead-bolt locks, security chains, electronic alarm systems and trip wires hooked up to a police station or private guard firm. Many suburban families have sliding glass doors on their patios, with steel bars elegantly built in so no one can pry the doors open.

5. It is not uncommon, in the most pleasant of homes, to see pasted on the windows small notices announcing that the premises are under surveillance by this security force or that guard company.

6. The lock is the new symbol of America. Indeed, a recent public-service advertisement by a large insurance company featured not charts showing how much at risk we are, but a picture of a child's bicycle with the now-usual padlock attached to it.

7. The ad pointed out that, yes, it is the insurance companies that pay for stolen goods, but who is going to pay for what the new atmosphere of distrust and fear is doing to our way of life? Who is going to make the psychic payment for the transformation of America from the Land of the Free to the Land of the Lock?

8. For that is what has happened. We have become so used to defending ourselves against the new atmosphere of American life, so used to putting up barriers, that we have not had time to think about what it may mean.

9. For some reason we are satisfied when we think we are well-protected; it does not occur to us to ask ourselves: Why has this happened? Why are we having to barricade ourselves against our neighbors and fellow citizens, and when, exactly, did this start to take over our lives?

10. And it has taken over. If you work for a medium- to large-size company, chances are that you don't just wander in and out of work. You probably carry some kind of access card, electronic or otherwise, that allows you in and out of your place of work. Maybe the security guard at the front desk knows your face and will wave you in most days, but the fact remains that the business you work for feels threatened enough to keep outsiders away via these "keys."

11. It wasn't always like this. Even a decade ago, most private businesses had a policy of free access. It simply didn't occur to managers that the proper thing to do was to distrust people.

12. Look at the airports. Parents used to take children out to departure gates to watch planes land and take off. That's all gone. Airports are no longer a place of education and fun; they are the most sophisticated of security sites.

13. With electronic X-ray equipment, we seem finally to have figured out a way to hold the terrorists, real and imagined, at bay; it was such a relief to solve this problem that we did not think much about what such a state of affairs says about the quality of our lives. We now pass through these electronic friskers without so much as a sideways glance; the machines, and what they stand for, have won.

14. Our neighborhoods are bathed in high-intensity light; we do not want to afford ourselves even so much a luxury as a shadow.

15. Businessmen, in increasing numbers, are purchasing new machines that hook up to the telephone and analyze a caller's voice. The machines are supposed to tell the businessman, with a small margin of error, whether his friend or client is telling lies.

16. All this is being done in the name of "security"; that is what we tell ourselves. We are fearful, and so we devise ways to lock the fear out, and that, we decide, is what security means.

17. But no; with all this "security," we are perhaps the most insecure nation in the history of civilized man. What better word to describe the way in which we have been forced to live? What sadder reflection on all that we have become in this new and puzzling time?

18. We trust no one. Suburban housewives wear rape whistles on their station wagon key chains. We have become so smart about self-protection that, in the end, we have all outsmarted ourselves. We may have locked the evils out, but in so doing we have locked ourselves in.

19. That may be the legacy we remember best when we look back on this age: In dealing with the unseen horrors among us, we became prisoners of ourselves. All of us prisoners, in this time of our troubles.