A fuse is lit in Lebanon

There are growing fears that the political powder keg in Lebanon may be on the verge of blowing up - yet again. Although there is mounting pressure on the government of President Amin Gemayel to bring about reconciliation between Christian rightists and Lebanese leftists, there are few indications that the current flurry of meetings with political rivals will permanently resolve the crisis.

The state of affairs was best reflected in a political vignette involving a former prime minister, a Sunni Muslim, who went to the Baabda presidential palace to Mr. Gemayel, a Maronite Christian, with one question: Did the President understand what was happening around him?

The session was held shortly after the crisis peaked last week with the kidnapping of three Cabinet ministers by Druze militiamen. The Druzes have been angered by the government's refusal to heed their calls for reforms. The officials were released with a list of 10 demands from Druze leader Walid Jumblatt, who is also Lebanon's leading leftist.

In only five days, the Druzes have received widespread signs of support:

* Amal leader Nabih Berri, who represents Lebanon's largest Shiite sect, publicly backed the call for a redistribution of power, giving the Muslim sects a greater say in the Christian-dominated government.

* The newly formed National Salvation Front, which combines seven leftist political parties, a former prime minister, a former president, and includes Mr. Jumblatt, issued a statement in Damascus appealing to Mr. Gemayel to seek a dialogue with his opponents in order to avoid a total civil war.

* Through its state-controlled press, Syria described the Druzes' demands as ''legitimate,'' adding that they ''constitute the minimum acceptable to the sweeping majority of the Lebanese people.''

In effect, Gemayel is politically besieged.

Muslims now dominate the population, with the Shiite sect alone representing an estimated one-third of the population. And Syria surrounds roughly 90 percent of Lebanon's borders.

Beirut airport has become a symbol of the emergency. It was forced to close Wednesday after shelling from Druze positions. Through intermediaries, Jumblatt has said it will not be allowed to reopen until the government has responded to Druze demands, particularly one calling for the withdrawal of Lebanese Army troops from Shouf positions close to Druze villages.

Mr. Jumblatt's Progressive Socialist Party (PSP) and the National Salvation Front have both said the Army - as a symbol of government authority - would not be accepted in the Shouf until there is a new political arrangement. Every additional day the airport is closed is a serious blow to Lebanon's already troubled economy.

But sources close to the government now contend that the current situation has arisen because officials chose to ignore advance warnings that the airport would be held hostage.

Middle East Airlines did heed the warning and began moving many of its crews and equipment to nearby Cyprus two weeks ago. Only two aircraft were caught on the runway when the shelling began.

There are now strong suggestions from both diplomats and Lebanese sources that the government will soon have to withdraw from the Shouf. It will also have to end use of the airport for its air force in order to get it reopened.

But that would leave a vacuum in the volatile Shouf, since the Israelis are scheduled to withdraw in the near future. It would virtually open the way for an escalation in the already bitter fighting between rival Druzes and Christian Phalange militiamen.

The consequences of trying to remain in the Shouf, however, are evident in the fact the biggest base, at Kfar Matta, has been besieged for five days by Druze militiamen. And large amounts of military equipment, including 10 armored personnel carriers, have been captured by the Druzes.

Diplomats in the region are deeply concerned that long term the government will not move sufficiently to end the discord and the fighting. A high-level envoy compared the atmosphere in government circles to the final days of Richard Nixon's presidency, using words such as ''paranoid'' and ''paralyzed.'' He described top officials as ''feeling embattled and retreating among themselves.''

Meanwhile, the Druzes are apparently prepared to follow through with their threats. On Monday, the PSP issued a statement declaring, ''We will not drop our arms before our historical and inalienable rights are achieved.''

Berri has suggested that new national consultations be held between the Gemayel administration and a complex network of political parties to reach a formula that would revise the unwritten ''national covenant.''

The pact divided power on a now-outdated demographic basis in a 6:5 ratio in favor of Christians in all branches of government.