When you see a picture of Attorney General Edwin Meese squinting at marijuana plants seized in a raid in the Ozark National Forest, you may be tempted to conclude, as one critic of the marijuana laws did, that Operation Delta-9 -- last Monday's 50-state raid of which the Ozark operation was part -- was "just good propaganda." Certainly Mr. Meese understands that it is probably impossible to stamp out marijuana entirely. It is easily grown and in considerable demand. Possession and use of marijuana in small amounts is a minor offense now in most states.

Even so, we think Mr. Meese and his 2,200 federal, state and local comrades were not engaged in a quixotic enterprise. For one thing, while this country asks its Latin neighbors to take politically costly steps to stamp out their drug business, it behooves Americans to do something visible and major about their own. And if marijuana use is common, there is good evidence -- about as good as is possible, considering that the activity is illegal -- that marijuana use is less common in the 15-to-25 age group than it was a few years ago, and it may very well be less common in older age groups as well.

So the predictions commonly made by marijuana advocates in the 1970s that the habit would become well-nigh universal have not come to pass. A dozen years ago you could not refute claims that marijuana smoking was harmless, and you had to concede that some of the claims made against it were exaggerated. But now, after a decade in which perhaps 30 million Americans have smoked marijuana, evidence of harm -- harm on the order of that caused by tobacco and alcohol -- is accumulating. It would not be surprising, then, in a nation where cigarette and liquor consumption is declining, if marijuana consumption were declining too.

In the 1970s it was said that marijuana, like alcohol, could not effectively be prohibited. But it was forgotten that, in the century up to repeal, alcohol use was vastly reduced in the United States, partly by legal prohibition, more by persuasion and the power of ideas. Alcohol use increased after repeal, but to nothury levels. Now it seems that the country has reached an equilibrium on marijuana. Americans know it's unhealthy and use it less often. And they insist, properly, on enforcing the law against commercial pro Mr. Meese's raid in the Ozarks and Delta-9 serve a useful purpose not just in making the business of marijuana less secure but in underlining Americans' intention that this law should be enforced.