Most of the democratic governments in the hemisphere are now under siege by the drug mafia. Panama, however, is the first country that is owned by the mafia. In other countries, the mafia has infiltrated the army and is a major threat to civil authority. In Panama, it has taken over the army and, through Gen. Noriega, the country.

This is a hemispheric war. We are confronting one of the wealthiest networks of organized crime in history. Billions of dollars flow annually into mafia coffers. Narcotics traffickers, in unholy alliance with guerrillas and terrorists, now pose a threat to the rule of law far more dangerous than we have ever known. Thousands of government officials throughout the hemisphere are being intimidated daily by the narco-terrorist campaign. From supreme court justices to city officials, from Bolivia to the Bahamas, officials who do not cooperate are threatened with death in a way that is unimaginable for the average U.S. citizen to comprehend.

So by definition the threat is beyond the control of any individual nation. It should mobilize the nations of the hemisphere to act through the Organization of American States, both for self-protection and to forestall the temptation of unilateral U.S. action in the event of danger to the Panama Canal.

The words of the Rio Treaty are clear: "If the . . . sovereignty or political independence of any American State should be affected by . . . any fact or situation which might endanger the peace of America" then the OAS "shall meet immediately" to determine a course of action.

The drug mafia is that kind of threat. Military aggression is not a prerequisite to OAS action. President Kennedy referred to this same kind of threat in summoning a meeting of the American nations to deal with the threats to the peace from economic and social injustice.

The United States cannot do the job alone, nor should it. What is demanded is a firm stand by the entire hemisphere totally isolating the outlaw regime, diplomatically, economically and financially. All the nations should withhold recognition from Panama's rump president and withdraw their diplomatic recognition, as Argentina has done.

The United States' past actions have placed it in a weak position to advocate such joint action. The administration sat by when Noriega rigged the last election and when he sold out to the drug lords. It sat by when his duplicity was apparent to all.

Within the OAS, the position of the United States is no better. This is a classic case in which shortsighted policies finally have come home to roost. The United States has helped to emasculate the OAS by ignoring it in the problems of Central America for the past eight years. Now we are taking steps to destroy the OAS infrastructure by refusing to pay our dues. We are almost a full year in arrears. Vernon Walters, speaking of the U.N. in these columns just a few weeks ago, maintained that "as a matter of principle, it is un-American not to pay our debts." Apparently that applies to the rest of the world, not to the Western Hemisphere.

Right now the Panamanians are fighting a major battle against the brazen grasp for power of the drug lords in Panama. The threat is clear. It is time for the nations of the Americas totake a stand, and the OAS is the natural place to do it.

The writer, who was assistant secretary of the OAS in 1975-83, practices law in Washington.