SHAME, KHADAFY! NAUGHTY! President Reagan invoked economic sanctions on Libya last week because of its reputation for harboring terrorist camps and antipathy to civilized intercourse. While giving his prepared statement, Mr. Reagan proved he can still act; he scared the daylights out of many Americans as he led up to his announcement of economic sanctions--instead of which our ears were prepared to hear a solemn declaration of war. But what of it? The press quickly seized upon the fact that economic sanctions by the U.S. alone will hardly cause Khadafy to break his stride toward utter chaos in the Mediterranean basin. What's a poor president to do? Mention has been made of assassination. The CIA, no doubt, is ready to take a healthy swing at Khadafy, given authorization. Given no authorization, the CIA has probably bungled several attempts already. Mention has also been made of rallying our European allies--which should more correctly be stated, 'European acquaintances,' given the European community's record of alliance with U.S. actions since WWII--to invoke similar economic sanctions. Were it possible, such a course would definitely damage Libya; unfortunately, possible it is not. Subversion of Khadafy's regime might be a good ploy. Probably, though, the patsies in the State Department have spent seven sleepless nights coming up with reasons why subversion would occlude the chances of a rapprochement with the Soviets. We, from our vinyl armchairs so solidly rooted to the carpet in front of our television sets, recommend a completely different approach to the problem of Libya. (It is the same approach as our solution to the problem of the Soviet Union, by the way, in case it sounds familiar.) What? Oh, we think Khadafy's Libya should be disarmed, dispirited and put into a state of disarray by means of socio-cultural weapons, of which we have an incredible arsenal, easily deployed. We should defame Khadafy with videotapes of aerobic workouts, Rambo films, new sofa sleepers, walk around stereos, under the counter coffee makers, golden oldies and broadcasts of "The Cosby Show." Khadafy's regime would buckle in six weeks under such an onslaught of the best mediocrity America can muster; in ten weeks with average doses of pop culture. Khadafy can handle assassinations, missiles, fleets sailing nearby and political threats. What Khadafy could never handle would be wave upon wave of Care Bears, music videos, campaigns for anti-plaque toothpaste, chocolate chip cookies and gourmet ice cream. He'd surrender under a deluge of commercialism. It's a course of action we highly recommend. It is indefensible; no other country in the world save Japan and, maybe Taiwan, can compete with the firepower of American advertising. Khadafy's people would forget his ugly face quicker than he could say, "Anti-imperialism." The only problem with this is what may happen in ten years or so--Libyans might prove such quick studies in commercialism that we'd have to enact protectionist measures to keep them from putting Americans out of business.