Israelis debate 'right to know' vs. security.

How free a press can a democracy allow itself when it lives permanently on the edge of war? This question has been revived with the closure of an Israeli newspaper last week for three days at the order of the nation's military censor.

The daily Hadashot was shut down for a relatively trivial breach: its revelation that the Israeli Defense Ministry had set up a commission of inquiry into the charges that two of the four Arabs killed after hijacking an Israeli bus last month had been shot after their capture. The paper had flouted the law that calls for submission to the censor of all material related to military matters.

It was the first time in more than 30 years that an Israeli newspaper has been closed for censorship violations, not including the Arab newspapers of east Jerusalem which are often shut down for publishing articles that might incite violence.

Under emergency rules dating from the time of the British mandate, all articles dealing with security matters must be submitted to the military censor. Material subject to censorship was later expanded to include oil, immigration from certain countries, and foreign loans. The Israeli press and public almost unanimously accept the need for some sort of censorship in view of the perceptible danger of providing enemies with useful military information.

''I feel more comfortable having a knowledgeable censor going over my copy than having to rely on my own sense of what might or might not be useful to the enemy,'' an Israeli journalist says.

The problem begins when the censor extends his reach to the area of ''public morale.'' Members of parliament charged several years ago, for instance, that the censor had banned publication of the fact that an Army officer had been convicted for murdering Arab prisoners during the 1978 incursion into Lebanon. The fear is that the authorities will extend censorship to the political sphere in the name of the ''national interest.''

In 1975, the Labor government tried to make censorship applicable to top-secret communications between Israel and foreign governments and to secret meetings between Israeli diplomats and representatives of countries with which Israel has no relations. The Israeli Journalists' Association and the Foreign Press Association in Israel condemned the move, declaring it would do more harm to Israel than any possible leak would. The government eventually backed down.

Foreign reporters occasionally outflank the censor by not submitting copy to him or by going abroad to file. Several years ago, a CBS reporter in Israel flew to Italy to file a story about a banned Israeli book alleging that Israel and South Africa had cooperated in the development of nuclear weapons. When he returned to Israel, his press accreditation was revoked.

New York Times correspondent David Shipler got off with a mild rebuke last month for filing uncensored stories on the deaths of the bus hijackers. Israeli military correspondent Hirsh Goodman estimates that less than 1 percent of material submitted to the censor is banned.

The Israeli press is normally free-wheeling and highly critical of any government. While the press accepts the need for censorship, it does not accept it at any cost. Successive governments have indicated unease about where to draw the line between the national interest and the interests of democracy. In 1951, the government of David Ben-Gurion reached an agreement with the Editors' Committee, made up of representatives of the country's newspapers, to limit its broad powers of censorship and to refrain from closing down papers that violate censorship rules.

Hadashot, which began publishing a few months ago, did not enjoy the protection of this agreement since it was not yet represented on the Editors' Committee.

The anomaly of press censorship in a country that prides itself on being a democracy was addressed by Haim Zadok when he served as justice minister in 1976 : ''While we are proud that Israel maintains the freedom of its press in its difficult situation,'' he said, ''the government is obliged to limit this basic principle in the face of an even more basic principle - the protection of the most vital interests of the state.''

The other side of the coin was expressed in a Jerusalem Post editorial: ''There are times when a democratic nation to protect itself must limit the information given to public disclosure.'' This, the paper declared, was tolerable ''only as long as the red pencil strikes strictly at the proper targets and that what the public is told is otherwise complete and credible.''