WHEN Secretary of State Warren Christopher arrives in Hanoi tomorrow, he will pull back the curtain on what most Americans perceive as a faceless and monolithic Communist regime.
Mr. Christopher expects to meet with the former house painter and son of peasants who is seen as the most powerful man here today: Communist Party General Secretary Do Muoi. He plans also to talk with President Le Duc Anh, a general who fought US troops and oversaw Vietnam's occupation of Cambodia in the 1980s.
Christopher will enact President Clinton's decision to establish full ties 20 years after Hanoi's forces defeated US ally South Vietnam.
The top US diplomat will find Vietnam's leaders committed to opening up their infant market economy to foreign investment. Mr. Muoi, Mr. Anh, and Vietnam's reformist prime minister, Vo Van Kiet, differ on how fast to push for economic change, but they all agree that it is necessary.
Political liberalization, on the other hand, is elusive. None of the leaders openly advocates abandoning the party's monopoly on power. ''I don't see any Gorbachev here,'' says one Hanoi-based diplomat.
Vietnam's top three leaders, each of them in their 70s, earned their stripes fighting for independence and communism. The next generation of party leaders is more likely to include technocrats than veteran revolutionaries.
Vietnam's postwar isolation from the West has made it hard for outsiders to understand leadership and policy battles here.
Diplomats and party officials, speaking on the eve of Christopher's visit, say that trying to identify the most promising stars in the party is like reading tea leaves.
However, the style of leadership and the qualities needed to rule in this one-party state are somewhat less obscure. A tradition of collective leadership, established by founding party member Ho Chi Minh, remains the norm. The party discourages the emergence of a single, dominant leader. While reaching a consensus takes time, a power-sharing arrangement is one way, party officials say, to keep a potential Vietnamese Gorbachev from gaining too much influence.
Most people interviewed say they expect all three senior leaders to step down at the same time, possibly at the Eighth Party Congress planned for next spring. Muoi, Anh, and Kiet have equal stature within the party and are said to want an orderly succession of power.
Collective leadership doesn't preclude political factions, however. Observers often describe the party as balanced delicately between reformers clustered around Kiet, and conservatives - including most senior Army officers - siding with Anh and Muoi.
Diplomats say such an analysis is too simplistic. The differences within the leadership, says one, depends on ''concrete issues.''
Vietnam's Army, for example, has historically played a political role second in importance only to the party. It strengthened its hand after Vietnam's main benefactor, the Soviet Union, disintegrated in 1991, leaving Hanoi alone to face its traditional rival, China. The Army has since called repeatedly for vigilance against so-called ''peaceful evolution,'' the threat of reforms supported by forces hostile to communism.
But one European diplomat says Prime Minister Kiet may have bought off potential Army opposition to economic reforms by allowing the defense ministry to operate a commercial telephone network in competition with the lucrative state monopoly.
Kiet's recent foreign-policy successes would seem on one hand to bolster his continuing efforts to open up the economy. In the last month alone, Vietnam won diplomatic relations with the US and entry in the Association of Southeast Asian Nations, a former adversary.
Another European diplomat argues, however, that Kiet's very success abroad gives ammunition to the most conservative Communists. They can point to foreign policy triumphs as proof that Vietnam must preserve the political stability - and one-party rule - that created necessary conditions for its acceptance into the world community.
In the long run, some analysts say the party's leaders know it cannot monopolize power forever. They're trying, therefore, to buy time to evolve into a nationalist, authoritarian party, similar to those that rule in some other Far East nations.
What, then, must the next generation of leaders do to climb the political ladder in Vietnam?
Nepotism is not necessarily a disadvantage, party officials admit. Nong Du Manh, chairman of the National Assembly, is one of the youngest members of the 17-member Politburo. Party members and diplomats suggest that one factor in his fast ascent is a rumor that he is the unacknowledged son of Ho Chi Minh, who allegedly never married. Most analysts dismiss it, but Manh has not denied it.
A war record is less important today than an image of moral incorruptibility. More important is pragmatism and the management skills needed to build a healthy economy.
Phan Van Khai, a Soviet-trained economist working now as deputy prime minister, is seen by many as a likely successor to Kiet. Mr. Khai, a southerner like Kiet, is a key figure in Vietnam's economic transformation.
Dau Duy Tung, a conservative ideologist ranked fourth in the Politburo, is mentioned as a strong candidate for general secretary.
Manh, the National Assembly chairman, has no strong convictions according to one diplomat. If true, this may make him an attractive choice for power brokers looking to choose a malleable senior leader.