AS BARBARIC as it may appear on our television news, Col. Muammar Qaddafi has ample cause to gloat these days. The assassination of President Sadat has removed a second target from his publicly proclaimed list of leaders accused of betraying the Arab and Islamic cause by cooperating too closely with the United States. The first was struck from the rolls almost two years ago with the overthrow of the shah of Iran.

Anwar Sadat and Mohammed Reza Pahlavi are gone, but must they be forgotten by the United States after the eulogizing and hand-wringing are over? Only if we are prepared to accept the demise or capitulation of additional targets on the list.

Can we risk the consequences for our strategic and oil interests of hostile regimes at the entrance to the Mediterranean, on the narrowest choke point at the Straits of Sicily, on the Red Sea across from Jeddah, on the coastal Horn of Africa near the Straits of Hormuz and in the energy heartland itself?

If not, then we would do well to reassess the best way to assist King Hassan of Morocco, Presidents Bourguiba of Tunisia, Numeri of Sudan, and Barre of Somalia and the monarchs of the Arabian Peninsula who are all on Qaddafi's list.

Some will contend that this apocalyptic forecast overstates the importance of Qaddafi, but that has been offered as an excuse for ignoring him for over a decade. It is time to admit the truth which is so unpleasant to a myriad of Western interests. Full details about the assassination will not be available until after Sadat's presumed successor, Hosni Mubarak, has consolidated power. And we may not know the assassins' links with certainty even then. But there can be no doubt that they received some degree of suport or encouragement from Libya.

Qaddafi's guilt does not depend upon evidence trying the assassins to renegade Egyptian Gen. Saadeddin Shazli's headquarters in Tripoli or to the numerous cells of youthful Islamic fundamentalists which Libya has trained, armed and funded. Qaddafi is no less culpable if the assassination was executed by Egyptian zealots who had no Libyan contact other than the steady stream of religiously couched anti-Sadat invective from a clandestine radio station established in eastern Libya as long ago as 1973.

To be sure, Western sophistry can be employed to obscure these current facts and ample evidence of prior threats and attempts. But we fool only ourselves, not the countries of the Middle East where perceptions are as important as reality.

Unfortunately, intimidation works except in those exceedingly rare individuals like Anwar Sadat. Therefore, Qaddafi's gloating is more than offensive to our humanitarian instincts...it is threatening to our geopolitical interests.

Sadly, we can do nothing to prolong Sadat's life, but we can at least take steps to minimize the threat of intimidation presented by his death.

The Reagan administration made a start some months ago by condemning Libyan subversion, a stand long preached to deaf ears by the late Egyptian president and his colleagues. But condemnation may prove to be the easy part because the opportunities for damage control have been limited by years of drift.

Egypt's tragic experience serves to remind us that the United States can provide little internal security assistance at the muzzle end of the weapon of international subversion. Yes, we can sell massive quantities of sophisticated military equipment to Sudan and other target countries, but this will never stop determined assassins, and may, in fact, encourage unrest by raising the American profile and presence.

Similarly, we can suggest a willingness to intervene with our own forces as President Reagan did last week. But such ill-defined pledges risk further alienation while possesing little credibility in the presence of American oil installations and employes who could be seized as hostages long before American forces could be deployed.

We can also hope that the social, religious and economic problems endemic to the region be resolved. But their solution is way outside American control.

Finally, some argue that we can enhance regional stability by abandoning the policy for which Sadat died, but that only serves to reward the intimidators without satisfying their non-negotiable demand for the abandonment of Israel.

If there is little we can do at the muzzle end of international subversion, then we must turn our attention to the breech end of that weapon. In other words, we must attempt to interdict the funding, arms and propaganda at their Libyan source.

The prospects for a direct Egyptian assault on the Soviet-armed Libyan fortress are not promising. The United States would gain little political mileage -- let alone moral stature -- by resorting to Qaddafi's own methods of clandestine assassination. But even if we cannot achieve an immediate or decisive interdiction of Libyan subversion by removing Qaddafi, we can at least curtail Western support for his terrorist regime.

This can be accomplished by renouncing business-as-usual, regardless of whether that business is pumping Libya's oil, liquefying her gas, clamoring for her construction contracts, investing her petrodollars, meeting her import and technology requirements, consuming her petroleum or grasping for whatever other piece of that multi-billion-dollar pie we can get our hands on.

Admittedly, that policy will require unusual bureaucratic and corporate courage. But such a collective resolve would hardly rise to the level of Sadat's personal valor in journeying to Jerusalem and accepting the dying shah. If we are to instill courage in the moderates within the new Egyptian government, in other Arab states and even among the Libyan population, the United States and its allies must break the commercial links which finance Qaddafi and create his aura of invincibility.

Much of this disengagement will proceed from events, but the administration can begin by putting some muscle behind its request to American companies to withdraw their several thousand American personnel from Libya.

The companies profess to want an unequivocal order before they risk the shutdown of Libya's petroleum industry, an embargo on its exports to the United States, the nationalization of their remaining assets and the possiblity of jeopardizing those personnel.

It is far from certain that they would be happy with such a clarification, but we should recognized that the State Department is equally reluctant to accept responsibility and perhaps government liability. So the companies ignore State's widely publicized request, and Qaddafi and his erstwhile imitators are reinforced in the conviction that the capitalist world is more enticed by Libyan oil and profits than it is repelled by his support for terrorism and subversion.

The administration is far from helpless in this intolerable situation. With no diplomatic representation in Libya and a military encounter only just concluded, State has every justification -- even responsibility -- to declare American passports invalid for Libya. A similar step was taken during the hostage seizure in Iran, but surely State does not have to wait until hostages have already been seized.

There are, of course, risks. Perhaps a highly visible withdrawal would precipitate the hostage situation which it was designed to avoid. But will waiting make it any less likely, given the confrontation course upon which Qaddafi is embarked?

It is far more probable that such an action would lead to nationalizations, but there are legal remedies -- albeit weak ones -- and, ultimately, the United States government may have to provide compensation anyway for assets jeopardized for strategic interests.

Although withdrawal of personnel would be designed to protect American citizens and to give the administration greater freedom of action to deal with future provocations, it would also affect Libya's oil industry.

We don't have to attribute indispensability to American technicians in order to recognize that their absence would hurt Libya. Many of the ablest Libyans have fled the repressive regime. It will be difficult to replace either nationality with British, French or Italian technicians, for the oil industry is booming everywhere and Qaddafi's outbursts have not been aimed solely at the United States over the past 18 months. Nor are Soviet technicians a real alternative, for they have their hands full with Russia's oil production problems and are unfamiliar with the American equipment and techniques generally employed in Libya.

Thus, Libya's oil production could wind down, and its extremely complex gas liquefaction would be likely to shut down completely.

But even if Libyan oil sales were not interrupted by production problems, the withdrawal of personnel would likely prompt an embargo of shipments to the United States, which ran at a level of 570,000 barrels per day during the first six months of this year.

But an oil embargo might not be all bad, for our third largest supplier is also our most expensive. At a landed cost of $40.53 per barrel, the United States paid Libya well over $2 billion for a half year's imports...enough to purchase a lot of Soviet arms and fund plenty of subversion.

Although it has been argued that we cannot do without Libyan oil, that argument tends to disappear when, as now, the Libyans price it at an unrealistically high level. An embargo would certainly hit different refiners in different ways but that is an argument for arrangements to share sweet crude, not an argument for perpetuating disproportionate dependence up Qaddafi.

There is, however, another view of the oil supply relationship -- Libya's. Libya sold 40 percent of its oil to the United States during the first half of 1981. In the currently slack oil market, it is far from certain that Libya could readily find alternative markets for its high priced oil. Libya's crude is better suited to American than to European product slates. Moreover, market considerations which harm Libya might be reinforced by diplomatic representations to allies in the industrialized nations, and the moderate Middle Eastern producers, all of whom have an even greater interest in regional stability than we do.

We must undertake urgent efforts to stop subversion at its Libyan source by abandoning 12 years of a business-as-usual relationship with the Qaddafi regime. No one would argue that those efforts are costless or riskless but the hardships pale by comparison to those incurred by a continued drift which encourages Qaddafi to work his way down a list of target countries. We cannot bring back Anwar Sadat, but neither can we permit him to have died in vain.