While Mubarak and Qaddafi mend fences along their border

Libya and Egypt have reopened their border on the eve of President Mubarak's visit to Washington. Although news to Reagan, it appears to be part of a gradual Egyptian reentry into the Arab fold.

In a move marking an abrupt change in Egyptian-Libyan relations, the two countries have agreed to open their common border to limited traffic for the first time in three years.

The Feb. 1 announcement comes on the eve of Egyptian President Hosni Mubarak's first official visit to Washington. And the recent history of hostility between the two countries and the Reagan adminstration's antipathy toward Libya make the Egyptian move and its timing all the more intriguing.

Prior to his tour abroad to four West European countries and the United States, Mr. Mubarak made a stream of statements in speeches and interviews emphasizing: Egypt's identity as an Arab-African nation and its commitment to a nonaligned policy; moves toward the Soviet Union; and a frequently repeated offer to renew relations with the Arab world.

''This strategy has been emerging over some months,'' said one Western diplomat, commenting on Mr. Mubarak's attempts to tone down Mr. Sadat's somewhat strident pro-US and anti-Arab approach. ''But the timing is there. They're laying down some markers, to show Washington that Egypt has options.''

Mr. Mubarak's talks with the Reagan administration will deal primarily with future US military and economic aid to Egypt. The Egyptians are expected to receive an increase in US military assistance from $900 million to $1.3 billion a year. In addition, the Egyptians will ask Washington for more ''flexibility'' in spending and allocating US economic aid credits.

Also in the background of the Egyptian-American talks are the progress of the Palestinian autonomy negotiations and the April 25 Israeli withdrawal from Sinai in April. According to diplomatic analysts here, Egypt is quietly sounding out Washington's responsiveness to Egyptian needs, and the quality of post-April Egyptian-American relations.

Egypt is also placing emphasis on its links with the Arab world and its vested interests there. Over 200,000 Egyptians are currently working in Libya, according to the Egyptian Foreign Ministry. The reopening of the border, said a ministry spokesman, was part of Egypt's continuing efforts to improve its relations with Arab countries.

Those allowed over the border will be primarily Egyptians working in Libya, according to the Egyptian Information Ministry. The first group crossing Feb. 1 are 27 Egyptian teachers and their families, returning to Egypt for the midyear school holiday.

Monitor contributor Tim McGirk reports from London:

Egypt and Libya, once considered the most durable enemies in the Mideast, appear to have been conducting secret peace negotiations for several months, according to Arab and Western diplomats here.

Although feuding Egypt and Libya had both readied troops along their Saharan border last summer for a final showdown, hostilities ceased abruptly after Anwar Sadat's assassination in October. According to British and American diplomats, one month after Sadat's death, a relative of Col. Muammar Qaddafi arrived in Cairo on a secret visit with a conciliatory message.

The envoy was Colonel Qaddafi's cousin, Ahmad Qadhafadam, the chief of Libya's secret police. He was received by high-ranking officials in the Mubarak government. US and British diplomats in London were alerted to Qadhafadam's secret visit because the Libyan police chief stopped over in Britain en route to Cairo, they claim. This was followed up by an exchange of letters and ''regular telephone contacts'' between the Tripoli and Cairo governments.

One Egyptian official claimed that Mr. Mubarak insisted on one condition for ending the hostilities: that Colonel Qaddafi immediately withdraw his troops from Libya's border with Sudan. The shaky regime of Sudan's President Jaafar Nimeiry has been one of the few Arab supporters of the Egyptian peace treaty with Israel.

No one else in the Middle East has been a more violent critic of Camp David than Colonel Qaddafi. But according to Arab diplomats, Libya's radical leader was mollified by Egyptian assurances that Mr. Mubarak would not persist in the Palestinian autonomy talks unless Israel lets the Palestine Liberation Organization join in.

One US diplomat remarked, ''Qaddafi has a past history of bending to pressure - for short periods of time. He may see peace with Mubarak as an insurance policy against an attempt, inspired by the Reagan administration and carried out by Egypt, to topple his regime.''