TWO WEEKS AGO, the people in the house across the street from mine were robbed at gunpoint. Shortly before that, a man walked down a nearby street and kicked in some store windows. Not too long after that, there were two burglaries down the block, and just the other day I came across a robbery in progress. I can identify the gunman. He is one of several thousand men, aged 19 to 30, weighing 160 pounds, last seen running away with a paper bag. It's full of someone else's money.

I cite this as a way of saying that I didn't need the latest crime statistics to prove to me that crime in Washington is way up. You can feel it on the streets and you can hear it in the talk of your neighbors. You can tell there is something going on. It's depressing.

But what's really depressing is the realization that the only way the police could have stopped the incidents from occurring was by having a man on the scene at the time they happened. Since there was no cop in front of the house across the street, some men entered it, held up the people inside and took what they wanted.

It was the same with the man who kicked in the windows and the same with the burglaries down the block and the same with the stickup of the store that I happened upon. In all those cases, the cops came quickly -- very quickly, actually -- but it was too late. The ubiquitous thief with the universal windbreaker was off and running. Neither the victims nor the police had had much of a chance.

This is not the impression you would get from the people who speak for the police. They are now embarked on a campaign to convince one and all that crime is going up substantially because the number of police is going down. That this might be nothing more than a coincidence, they would never admit. Instead, they insist that one follows the other -- cause and effect and all that. This is the position of the police brass and the police unions. On this they are agreed.

On this, they are also wrong. It is regrettably true that major reported crimes went up 29 percent in the third quarter of this year compared with last year, and it is also true that the number of policemen or women has decreased from 5,070 in 1971 to 3,600 today -- with plans for possible further reductions. But it is also true that crime decreased in years when the police force also decreased. Specifically, from 1975 through 1978, the police force was reduced by 647 officers and the total number of major crimes also decreased. What the statistics indicate is that there is no pattern. Crime does what crime wants.

No one would argue that the crime rates has nothing at all to do with the size of the police force. It has to. Logic and experience tell you that. But what logic and experience do not tell you is the point at which you have enough cops and the point which you have nothing more than the fiscal version of wretched excess.

Should there be one cop for every block in the city -- three shifts a day? Should there be one cop for every other block and two for the really bad blocks? To stop most crime, that is the kind of numbers you would need. It is what would have been necessary to stop the house across the street from being hit, and it's what it would have taken to stop the robbery that I witnessed. If a cop had been in front of the store, the robber would have gone to another store.

And if the cop had been on the block, the robber would have gone to another block and then, maybe, to another block and then, maybe, to another section of town. The point at which you have enough policemen to stop crime in its tracks is the point at which you turn the city into an armed camp -- a cop on every corner. We have neither the will nor the money for that.

The truth, of course, is that there is a lot more to an increase in the crime rate than the size of the police force. There is, as the police themselves acknowledge, the economy and unemployment and the availability of drugs and maybe lots more -- lots we don't understand. The size of the police force is just a part of the larger picture -- just a piece of it -- and the trouble is that when you increase it, you decrease something else -- maybe schools, maybe recreation. It all comes out of the same pot, and it is the pot that is getting smaller, not only the police force.

The result is what you could call appropriaton by hysteria. The school system, which is to good management what the ayatollah is to women's rights, is playing politics with the education of children, yelling bloody murder and taking out its budget cuts on the necks of good teachers. The police department, not to be outdone, is conjuring up the specter of a crime wave.

The city has to make choices -- not easy choices, but choices nonetheless. It would be comforting if there were more cops, but it would be comforting, also, if there were more teachers, more sanitation men and more recreation workers and more judges, too. But what would be most comforting is if the decision on what services to trim is based on what is best for the city as a whole and not the interest of a particular union or a particular department -- based upon what we know, not upon what we fear.