The United States Marines were sent into Lebanon a year ago - they landed on Sept. 29 - for the purpose of letting the Lebanese choose their own government. This week, for the first time, US guns fired on the soldiers of one faction of Lebanese while those soldiers were trying to influence the choice of government.
The immediate purpose behind the actual firing on Druze positions in the mountainous Shouf region was to protect the US marines on the coastal plain below.
But the effect of the firing was to prevent the Druze militiamen on the mountain from capturing the town of Souk al Gharb and improving their leverage in the maneuvering going on behind the scenes over the future complexion of the government of Lebanon.
It was incidental interference in the internal political affairs of Lebanon, but it was interference. The fact that it apparently had to be done for the protection of the marines underscored the ambiguity of the position of those marines in Lebanon. They were no longer in Lebanon to hold the ring. They are in the ring.
It did not matter whether they were in the ring incidentally, accidentally, unintentionally, or intentionally. The essential fact is that their very position on the coastal plain in the line of fire between different and rival Lebanese armed forces made them participants in what had become a civil war.
Both the Shiite Muslims in southern Beirut and the Druze Muslims in the Shouf mountain area are unhappy about the composition of the government of Amin Gemayel. They object to it partly because it is, or they think it is, loaded with Maronite Christians and hence unrepresentative of the entire Lebanese community.
The Druze and Shiite communities are also unhappy over the Gemayel government because it has come to terms with Israel and because it is supported and to some extent is influenced by the Phalangist militia, who are regarded as enemies by both Druze and Shiite factions.
Had there been no US marines controlling the Beirut airport, and had US naval vessels offshore not fired into the Druze positions in the Shouf mountains, it is probable that Druze and Shiite forces would by this time have taken the airport and south Beirut, and possibly even the whole of the city of Beirut.
The airport itself is a major bargaining asset in Lebanese politics. The Druze and Shiite factions are denied possession of that bargaining position by the presence of the Marines.
Syria is backing the Druze and Shiite factions.
The real question Washington faces this weekend is whether it is willing to go to war against Syria to save the regime of Amin Gemayel in Beirut.
Complicating the decision is the distaste of US allies who also have troops in Lebanon for any such activity. The French, Italian, and British contingents were sent in along with the US Marines for the purpose of getting the Israelis out of Beirut and out of the airport area - and thus allowing the Lebanese a chance to set up a government of their own and get it working.
This week many quarters in France, Italy, and Britain expressed disapproval of the US shelling of Druze positions, hence disapproval of the idea of interfering in the internal politics of Lebanon. It seems probable that if the US continues to play an active military role in the Lebanese civil war, the US Western allies will pull out.
President Reagan has several reasons for staying in and playing such a role. Withdrawal of the Marines under fire would be unpopular with his conservative constituents. The newly formed Lebanese Army has been trained by the US, hence Washington has a paternal interest in its welfare and survival. The Gemayel government, under US guidance, concluded an interim agreement with Israel and is therefore an active ingredient in current US efforts to obtain a peace between Israel and Lebanon.
The combination of these reasons explains why the marines were still in Lebanon this week, three weeks after they first took casualties in the Lebanese fighting. The first American casualties occurred on Aug. 29 when two marines were killed and 14 wounded.
President Reagan has an unpleasant choice to make. If he withdraws the marines, the almost certain consequence would be collapse of the Gemayel government and disintegration of the newly formed Lebanese Army. That in turn would put an end to the agreement worked out between Israel and the Gemayel government.
Washington would have to start all over again in its quest for peace along Israel's frontiers.
But if the marines remain and the US role in the Lebanese civil war escalates , the US will in fact be making war against Syria. And that in turn would put a new strain on US relations with the entire Arab community and with much of the Muslim world.
Also down that road lies the danger of military confrontation with the Soviets.
This week US relations with the Soviets were being conducted within the context of the most angry exchange of rhetoric since the Soviets invaded Hungary.
While the President wrestled with conflicting arguments for getting out or staying in Lebanon, the Congress in effect seems ready to wash its hands of the problem by moving to give the President permission to keep the marines there for another 18 months. Few on Capitol Hill in Washington wanted to be labeled either way about the marines in Lebanon.