Cairo — Algeria, one of the last bastions of hope for a mediated solution to the 2 1/ 2-year-old Gulf war, has abandoned its efforts to secure a negotiated settlement between Iran and Iraq.
Algeria has made no public announcement of its decision to stop its mediation attempts. But senior Arab diplomats say that Algerian Foreign Minister Ahmed Talib Ibrahimi returned from visits to Tehran and Baghdad several weeks ago convinced that ''Ayatollah Khomeini is prepared to sacrifice any number of lives in order to obtain a military victory.''
Algerian officials are privately quoted as saying that Ayatollah Khomeini needs the Gulf war as a means of preventing Iran from disintegrating.
On Feb. 6 Iran demonstrated its determination to continue the war when it once again hurled thousands of Iranian troops and hundreds of tanks and armed personnel carriers across the Iranian border.
As fierce fighting continues, Iraq has been stepping up its call for Arab support, presenting the latest Iranian assault as a threat not only to Iraq but also to the whole region. Iraq's call for Arab aid may have an ironic side effect: the return of Egypt, castigated for its peace treaty with Israel, to the Arab fold.
Senior Iraqi officials are frequent and regular visitors to Cairo.
Two senior Egyptian officials - Minister of State for Foreign Affairs Butros Ghali and Osama al-Baz, President Hosni Mubarak's senior political adviser - paid a surprise visit last week to Baghdad - the venue of the 1978 Arab summit conference that decided to boycott Egypt for its continuation of the US-Israeli-Egyptian Camp David peace process.
Mr. Ghali and Mr. al-Baz traveled to Baghdad to brief Iraqi President Saddam Hussein on President Mubarak's discussions in Washington about the Gulf war with President Reagan.
Senior Egyptian officials say Iraq had asked Mr. Mubarak to pass on a number of requests to the Reagan administration. These requests are said to have included:
* US pressure on Western Europe and Israel to stop economic and military aid to Iran.
* More US political, economic, and military support for Iraq.
Egyptian officials, interviewed by this reporter, refused to give details of the US response but said that the Reagan administration's attitude toward the Gulf war was ''encouraging'' and that the United States has ''a deep sympathy for Iraq's position.''
Egyptian officials insist that responsibility for security and stability in the Gulf lies with the United States.
Egypt, for its part, these officials say, is making its own contribution. Egypt has sold Iraq ammunition and spare parts worth $1.2 billion during the past year.
Egyptian volunteers, believed to number 7,000, have joined the Iraqi fighting force on the battlefield. But Egyptian officials insist Egypt is not willing to commit troops to the Gulf war.
Last month Naim Haddad, the speaker of Iraq's National Assembly, told an Egyptian weekly that Egyptian arms supplies were not sufficient. He called on Egypt to send regular army units to Iraq.
President Hussein is believed to have repeated the Iraqi request in a telephone conversation with President Mubarak on Feb. 5.
''Egyptian troops will never again cross the Egyptian border,'' a senior Egyptian official said. He added that ''the thousands of Egyptian workers in Iraq are allowing Iraqis to go to the front.''
The oil-rich but vulnerable Gulf states see Egypt as the only Arab country with the military potential to come to Iraq's aid.
Iraqi officials have hinted that Iraq would help Egypt break its isolation in the Arab world in return for more military support.
Egyptian officials respond to these hints by pointing out that ''the Arabs need us more than we need them,'' a reference to Egypt's demand that the Arab world acknowledge its mistake in condemning the Camp David accord.
These officials acknowledge the failure of Algeria's last-ditch attempts to mediate an end to the Gulf war.
They express the conviction that Iran is not strong enough to overthrow the government of Iraq's Saddam Hussein.
''But,'' a senior official said, ''if the Iranians do succeed, that's Iraq's problem. That is the price that Saddam will then have to pay for his stupidity in attacking Iran.''