The Reagan administration in Washington turned its foreign policy attention this week away from Lebanon and the Middle East to El Salvador and Central America. It did so for two reasons.
First, there was literally nothing useful it could do about Lebanon right now other than watch from the sidelines. Its actual operating policy (distinct from declaratory policy) had been to reshape Lebanon into a unified state under Maronite Christian leadership and oriented politically and economically to Israel.
That policy had collapsed. There were two ''observers'' in the room at the Lebanon conference which was reconvened in Lausanne, Switzerland, this week. They were Syria and Saudi Arabia. The United States was not in the room. It had become a minor factor in the Mideast equation.
Second, alarm bells have been ringing about the situation in El Salvador. Morale in the Reagan-supported regime and its Army is low. The Army has won no decisive battles for months. Guerrilla strength is believed to have been increasing steadily. Reports persist of the type of corruption and inefficiency that preceded the collapse of the Chiang Kai-shek regime in China in 1949 and the South Vietnamese regime in 1975.
No one on the outside can be sure whether the El Salvador regime can be salvaged. Three years of US military and economic aid have failed to change the basic situation. The rebel guerrillas have been able to maintain the offensive, and to increase their numbers and combat efficiency at least as fast as US aid has helped the official Army.
Some observers believe the regime can be saved only by commitment of US armed forces. Congress, inevitably, reacts by thinking it sees a repetition of the Vietnam story. There are too many similarities for comfort in Washington.
President Reagan attempted this week to head off either the possible collapse of the government or the possible need for US troops in combat by asking for an emergency special appropriation for El Salvador of $93 million.
The ensuing debate in Congress for the emergency aid puts the administration in a safer political position at home. If Congress refuses the aid and the El Salvador regime collapses, Mr. Reagan will blame Congress. If it votes the aid, there is a reasonable prospect the regime can be propped up and kept going at least through election day in November, after which its fate will seem of less importance in Washington.
The administration understandably wishes to avoid another foreign policy collapse coming soon after Lebanon and before the November elections.
Concern over El Salvador serves conveniently the secondary purpose of diverting public attention from the outcome in Lebanon. There, the US Marines are safely out of the action and aboard ships offshore. Their presence ceased to influence the deliberations among the Arabs themselves over the shape of Lebanon.
One interesting fact emerged early from the deliberations at the conference of the Lebanese factions in the splendid turn-of-the-century Beau Rivage Hotel in Lausanne. Syria, which is presiding over the process just as the US presided over the conference of a year ago between the Gemayel regime and Israel, is happy to keep Amin Gemayel as titular head of a new Lebanese goverment.
The first three days of the conference produced a cease-fire which was being substantially, not entirely, observed on the streets in Beirut on Thursday. The conferees then proceeded to work out arrangements for a new order in Lebanon in which the Muslim community will clearly have at least equal authority with the Christians and in which the Army will no longer be controlled primarily by Christians for the benefit of Christians.
The work of reconciliation among the various communities in Lebanon will of course require time. But the Syrians made more progress toward a reunified Lebanon in three days than the US has been able to make in two years.
The reason for the faster progress, of course, was that the purpose behind the Lausanne talks was to remake Lebanon within an all-Arab context, and oriented toward Syria, not toward Israel or the US.
Washington attempted this week to keep its hand in the area by pushing along what is called the Jordanian option. This consists of selling Jordan equipment for a Jordanian ''mobile strike force'' of 8,000 men plus 315 launchers and 1, 613 ''Stingers.'' A Stinger is a small surface-to-air missile with a combat range of three miles. The total cost of the package for Jordan is estimated at about $500 million.
The President went before a conference of the United Jewish Appeal in Washington on Tuesday, asking it to recognize military aid to Jordan as being in the interests of both Israel and the US. This may or may not head off a move in Congress by pro-Israel senators to block aid to Jordan.
The President said that strengthening Jordan would help to prevent Syria from trying ''to dominate the region.'' But the idea of using Arabs against Arabs seems to be difficult for Israel to accept. The President will have trouble pushing aid to Jordan through Congress. And NATO allies doubt that Jordan has any taste for being used, or presented as being used, as a counterweight to Syria.
There was talk in Washington of persuading Jordan to obtain a license from Yasser Arafat of the Palestine Liberation Organization to negotiate with Israel on behalf of the Palestinians.
But in an interview with the New York Times, Jordan's King Hussein ruled out direct negotiations with Israel any time soon. And besides, diplomats generally find it unrealistic to think that King Hussein would undertake any such mission unless he first has a license from Syria.
The President apparently still hopes to make progress toward a general peace in the Middle East without Syria. The chances are that sooner or later he will have to include Syria if he wants to get anywhere.