THE LIBYAN EMBASSY here in Washington now seems to have seized itself. Outside in the street, the police wearily put up the customary barricades while inside several of the embassy's management have taken themselves hostage. They are holding themselves incommunicado while they negotiate the terms of their release with themselves. Once again, it is the Libyans who are leading the way to new examples of revolutionary zeal and radical fervor.

But there is also an un-comic side to the affair. Four of the men sequestered in the embassy were ordered by the State Department to get out of the country by Monday night. The department believes them to be responsible for the recent campaign of threats against Libyan dissidents living in the United States. One publication disseminated here called for the "liquidation" of those who fail to support the revolution -- that is, the military regime headed by Col. Muammar Qaddafi. There's always a temptation to brush off that kind of talk as mere rhetoric. But four of Col. Qaddafi's enemies have recently been assassinated in Western Europe.

The Libyan Embassy here is hardly what you'd call a typical example of diplomacy. It's not quite accurate, first of all, to call it an embassy; it's the People's Bureau of the Diplomatic Mission of the Socialist People's Libyan Arab Jamahiriya. The World "jamahiriya" is translated as "congregation." At Col. Quaddafi's instigation, a committee of five students descended on the embassy last fall and took it over. Although they have been representing their government, they have refused to obtain diplomatic credentials. That raises a legal question about their present status. But since they have been acting as diplomats, the State Department says, it will treat them as diplomats. Because of Iran, it is leaning over backward to avoid an infringement of even the most farfetched definition of immunity. But the people whom it wants to expel are four of the five-man committee that is running the People's Bureau. A spokesman for the People's Bureau says that they won't go voluntarily.

This peculiar affair is another stage in the degradation of diplomatic usage. It's when they break down that the reasons for diplomatic conventions are most evident. Iran's seizure of the American diplomats in Tehran has inspired assaults on embassies elsewhere. Now it has led to this bizarre example, in which four Libyans are asserting their revolutionary right to organize the liquidation of their enemies from a house on 22nd Street.