Reagan's marines

President Reagan will likely get the backing he wants for a longer, bigger US marine presence in Lebanon - from both the Congress and the public. Congress wants to avoid a confrontation with the White House over Lebanon. It's uneasy about Reagan's go-ahead for airstrikes - to defend the other peacekeeping troops and the host Gemayel government's forces as well as the marines. This clearly means an escalation in the US presence. And institutionally, Congress can't and shouldn't give up, without resistance, its war-authorizing duties to the White House, at whatever level of conflict.

So a compromise, giving the White House room to maneuver with the marines and their backup force in Lebanon through next year's election, but invoking the War Powers Act, which acknowledges Congress's say in committing US troops, looks like the reasonable course.

This means basically endorsing the status quo - conceding Reagan the lead hand on that troubled front.

Now for the public. So far, Americans have been reacting to the call for US troops in Lebanon in the classic pattern. At first they were sharply opposed to sending the marines. But once the marines were in place in Lebanon, as part of the four-nation peacekeeping team to cover while the Syrians and Israelis supposedly withdrew, the public began to show no overall dissatisfaction. Americans don't like to leave a president hanging once troops are deployed - much as Congress doesn't want to be blamed for pulling the rug out from under the White House when the going gets tough. This is the way public and Congressional opinion went for Vietnam. It's the same pattern with Central America. And now with Lebanon.

Not unless it's proved the commitment of troops was clearly a terrible mistake - and we're not at that point yet in Lebanon, despite the loss of several marines in hostilities - will the public and Congress reign in such a military initiative. Ultimately, though the cost may be borne by others in lives and suffering, the burden of proof is the President's that his policies are right.

This is a serious responsibility now in the Mideast. President Reagan wants to shore up the Gemayel regime in the hope of fostering a government that can eventually reunite Lebanon. Syria, with Soviet backing, is sponsoring a Druze militia drive to positions near Beirut, to enhance the Syrian cluster of forces' position in Lebanon. The administration wants the marines present, while the fighting worsens, to salvage what it can in the vacuum left by the Israeli forces' pulldown to the south. A cease-fire has proved elusive - hence the clear warning to Syria and its clients that US firepower is poised potentially to do more than protect marines from direct attack.

Meanwhile, the Lebanese economy has been shattered. The succession in Israel's leadership to the south has not been resolved. Israel is enduring a guns and butter debate in its cabinet, with much of current US aid now just being rolled over to pay off earlier debt. Debt problems among the Arab nations are rising. Syria's own economy is under a lot of pressure, exposing its client status dependent on Soviet and Saudi aid. The Saudis have cut back a half billion dollars in their Syrian support.

So there's more involved in the Lebanon question than just authorizing the presence of marines, as their peacekeeping role escalates to a potential show of force. No wonder Congress hesitates to call the President's hand, whatever its misgivings.