Two bitter Lebanese rivals have much in common

They are called ''the mountain people'' - the rugged and tenacious survivors who fled to the mountains of Lebanon centuries ago to escape religious persecution and preserve the identity of their heretical sects.

The eyes of the world are now focused on the two little-known groups - Druzes and Maronites - who are locked in a second week of war. Their conflict in a 230 -square-mile area is threatening to become internationalized.

Ironically, of all Lebanon's 17 recognized sects, these two bitter rivals have the most in common: Their tight-knit communities have often taken up arms to protect their self-described ''racial purity.'' Although small in numbers, their political influence is disproportionate to their size. They are usually well-educated by third world standards, make good businessmen, and include many of Lebanon's wealthiest citizens.

Yet, they have fought each other sporadically for more than 120 years, with many startling parallels between the first war in 1860 and the current strife in the Shouf mountains.

The Maronites, numbering some half million, look at Lebanon as the eastern frontier of the Christian west. They see themselves as latter-day Crusaders, fighting to preserve Christianity in a sea of Islam.

They broke with mainstream Christianity in the 7th century under the hermit, St. Maron, the patron saint of monks who built retreats in the isolation of central Lebanon. Although they finally fully rejoined Rome in the 18th century, the Maronites have stuck to their own Arabic lethargy and own religious customs, including the marriage of priests, reflecting their independent streak.

They became a major factor in Lebanon, again ironically, through a relationship with the Druzes in the 16th century. The Maronites expanded into Druze areas of the mountains with the blessing of Druze Sheikh Fakhreddine, who was impressed with the friendly and hard-working Christians.

They quickly became the largest, most organized, and wealthiest institution in the mountains, which led to demands for power commensurate to their standing. But the Druzes balked, opening the way for the first round of religious strife. It was the forerunner to today's war. Some 12,000 were reportedly killed when the Druzes went on the offensive, expelling the Christians from their traditional areas, as they are doing again now.

Yet, the Maronites emerged politically victorious, as the French landed troops after the conflict to restore and protect the peace, not unlike the multinational peacekeeping force from France, the United States, Italy, and Britain today. As a result, the Maronites continued to dominate the mountains. More important, the war also established the principle that power was related to religious communities. This was formally channeled into the 1943 ''National Covenant'' dividing government jobs among the 17 sects upon independence from the French mandate.

In their current form, the Maronites are consolidated politically under the Phalange Party, although there are several smaller Christian parties. It was founded by Pierre Gemayel, father of the current Lebanese President, in 1936, and its rightist policies were strongly influenced by Spain's Franco and Italy's Mussolini, right down to the wearing of dark shirts.

The Phalange and its ''Lebanese Forces'' militia have effectively established a mini-state - the so-called ''Marounistan'' - collecting taxes, running newspapers and radio stations, running its own police and intelligence services, and even providing garbage services.

But the Maronites have lost the race with numbers, the basis in 1943 for winning the top jobs and a ratio that gave all Christians a 6 to 5 edge over the Muslims. Now they must either face perpetual conflict with the Muslims or agree to redefine Lebanon.

The Druzes, numbering some 300,000, have always looked at Lebanon as the western frontier of the Arab east, advocating that its economy, culture, language, and political orientation be like its geography, attached to the Arab world.

The Druzes broke with mainstream Islam in the 11th century, branching off the Shiite schism, and eventually fleeing from Egypt to the safety of the isolated Lebanese mountains.

Their beliefs are shrouded in mystery, even to as many as 90 percent of the Druzes, who must be ''initiated into the faith.'' Their ''book of wisdom'' is still written in Arabic script only by the hand of a religious leader to avoid outside access, and there are no converts.

The sect was named after Nashtakin al-Darazi, a Turkish tailor who became an early missionary but was subsequently disgraced and left the movement.

The Druzes have traditionally been among the most tolerant of other faiths, concerned mainly with the preservation of their own families and landholdings in Lebanon, Syria, Jordan, and Israel. Indeed, in Israel, their proven loyalty to the state has made them the only Arabs allowed to join the Army.

After the 1860 Maronite-Druze war, many Druzes fled to Syria. Those who love the scenic mountains overlooking the Mediterranean do not want to be pushed out again, which is why Druze leader Walid Jumblatt has taken a stand, calling for his men in the Progressive Socialist Party to take up arms again.

The Druzes' hold on the southern sector of the mountains was challenged in the aftermath of the Israeli invasion, when Israel's Christian allies moved in and set up Phalange bases in the Shouf, reopening old wounds. The Phalange argued that the Christian villagers needed protection, although in fact the two sects lived in comparative peace side by side.