ADDIS ABABA, ETHIOPIA -- Eight months after a youthful peasant army stormed into town in a blaze of automatic weapons and artillery, workers finally have carted away a charred Soviet-supplied tank that had been obstructing traffic on a busy street in back of the National Palace.

For the former rebels, now rulers, the rusting tank had become a monument to the defeat of longtime Marxist dictator Mengistu Haile Mariam.

But for many residents of this capital, the crippled combat vehicle reinforced tensions between civilians, mostly of the Amhara ethnic group, and the troops, most of whom are Tigrayans from the rural north and still regarded as outsiders here.

An uneasy peace rules here as former rebel leaders guide Ethiopia to democracy under a transitional government. Gunfire still crackles through the night, sandbags remain stacked outside government buildings, armed garrisons hole up in first-class hotels, and baby-faced soldiers ride pickup trucks mounted with machine guns or patrol on foot, their belts heavy with grenades and bullets.

One broken tank seems a small thing in the broad panorama of destruction and loss that accompanied three decades of civil war. Yet the reluctance to dismantle the apparatus of conflict has been striking among the mixed signals put out by the six-month-old government of President Meles Zenawi, the former Tigrayan rebel leader.

A climate of uncertainty is fueling a volatile mix of high expectations, fears, ethnic tensions and relentless economic decline that endanger the fragile democratic experiment in Ethiopia -- held out by the U.S. government and other Western supporters as a potential model for the rest of Africa.

One source of tension is a widening chasm of mutual incomprehension and suspicion between the mostly young men from rural Tigray Province who dominate the ruling coalition Ethiopian People's Revolutionary Democratic Front, and the professional class of urban Amhara that is viewed as necessary for recovery.

After an initial period of grudging acceptance and even hope, this sprawling, squalid and dangerously armed capital of three million is feeling anger and frustration with the Meles government.

Democratic Front soldiers, who have behaved with restraint and discipline, increasingly are provoked by verbal and physical harassment. A live grenade was lobbed over the wall of the U.S. Embassy recently, presumably in retaliation for U.S. support for the Meles government. And in an act unthinkable only a few months ago, some protesters recently hoisted the portrait of the widely detested Mengistu -- to nods of understanding among the city's disgruntled elite.

In southern and eastern Ethiopia, meanwhile, banditry and armed clashes are on the rise, testing the patience of a military force that so far has conducted its affairs with a minimum of bloodshed.

Meles, 37, regarded by Western governments as one of the most promising of a new generation of African leaders seeking to fashion a democratic order, has weighted his cabinet with capable technocrats. On paper, the government has respectable plans for everything from the first free regional elections to development policies aimed at weaning Ethiopia from dependency on food aid.

Yet the new leadership is hamstrung not only by scant government experience and the chaotic nature of coalition politics, but also by a formidable array of problems inherited from Mengistu, who fled into exile in Zimbabwe one week before the Democratic Front seized Addis Ababa on May 28.

"The treasury was stripped bare," said Abdul Mohammed, an Ethiopian consultant to relief organizations. The Democratic Front "inherited an economy that will only get worse before it gets better. They faced the demobilization of black Africa's largest army. Worse still, they faced a population that now associates change with destruction," he said.

So far, according to foreign and Ethiopian observers, the Meles government has been unable to move away from crisis management to the day-to-day business of running the country.

"People need something clear and concrete to be able to see that their lives will improve and not keep getting worse," said a Western diplomat who has strongly supported the new government. "We've given them the benefit of the doubt -- now they've got to show they're capable of good governance."

The government's policy statements on a liberalized economy and media, draft legislation for an independent judiciary, and appointment of a special prosecutor to try alleged criminals from the Mengistu regime all convey the impression of a genuine effort to introduce democratic institutions to a country with virtually no history of political freedom. The cacophony of public expression, from editorial criticism to protest marches, is a novelty in a society long submerged in terrorized silence.

The outward commitment to democracy, however, has been undermined in the public eye by unpopular policies and actions that include continued political purging, the detention without charge of at least 1,300 former officials of the Mengistu era, strict exit-visa procedures and what appears to be an uncompromising approach to the city's elite.

The government also is drawing pressure from families of thousands of victims of the old police state to quickly bring the guilty parties to justice.

As with most criticism, Democratic Front officials respond by calmly outlining the plans they say ultimately will prove them right.

"We don't want to have kangaroo courts," said Tecola Wolde-Hagos, a legal adviser to Meles. "If we rushed through trials without the proper compilation of evidence and without a democratic court system, then people would really criticize us. . . . We are starting, from scratch, a whole new system that is fair and just. If people are patient, it will work out in the end."

A similar response is offered to growing concerns among Ethiopians that the government's guarantee of self-determination for ethnic groups, up to and including independence, is accelerating the centrifugal forces that long have tugged at this country.

The de facto independent status of the northern Red Sea territory of Eritrea, which won a separate war against the Mengistu government and has its own provisional government, is perceived by many Ethiopians as a precedent for a Soviet-style breakup of the country.

Meles has argued that, in contrast to Mengistu's misguided attempt to bludgeon the Tigrayans and Eritreans into submission, the only answer to ethnic or regional grievances is to air them in a democratic forum. He has said regional elections, due this spring, will lay the groundwork for a federal system that will provide an effective escape valve for political and economic pressures that, in the past, have exploded into violence across a wide stretch of the country.

"We have a lot of pressure, directly and indirectly, to take precipitous action," he said in an interview late last month. "We have resisted and we will continue to resist. . . . For us, every day without a total breakdown is one on our side."

At the root of much of the unhappiness is economic hardship, which the new government has been unable to reverse. Its economic policy appears ambivalent: On one hand it espouses a vigorous free market; on the other, it advocates a large degree of state control -- a position that many observers perceive as a holdover from the Tigrayan rebels' early Marxist orientation.

Western donors, who were quick to express political support for the Meles government, have been slow to follow through on promises of financial aid.

Hefty aid packages, including a $550 million emergency infusion from a World Bank-led consortium and an ambitious new development program from the U.S. Agency for International Development, are in the works. But, said Willard J. Pearson, AID's representative to Ethiopia, "the resources haven't started flowing yet. It's all still at the promise level."

Western governments have been criticized across Africa for offering only minimal financial support for the democratic experiments they openly encouraged. In Ethiopia's case, the Democratic Front took power with the explicit endorsement of the Bush administration.

"It's fine to talk about lack of decisiveness and leadership on the part of the new government," said one international aid official trying to drum up donations. "But it is also incumbent upon the donors to act quickly and come up with the support needed. They must assume a certain amount of moral responsibility."

Among Ethiopians trying to read the signs of the new era, perhaps the least convinced are the urban professionals. "This is the new government's greatest challenge -- to win the hearts of these professionals and bureaucrats," said one African aid official. "Without them, even the loftiest plans won't work. These are the guys who can ruin the whole experiment without firing a shot."

A hard core of the elite was opposed to the Democratic Front from the outset. Some feared loss of privilege or fortune, some scorned the ragtag appearance of the occupying forces. Others feared the logic of force would ultimately overcome the impetus toward democracy. Many simply did not know how to communicate.

"They are clean, straightforward and naive boys, and as a class, we don't know how to speak to them," said one Ethiopian economist, who generally supports the new government. "We are accustomed to the Byzantine language and ways of the old order."

The Democratic Front has done little to reassure this group, which it perceives as having silently abetted the old regime. While many were compromised by their roles in Mengistu's government, army and security network, the Democratic Front has tended to paint the past with a broad brush.

The firing of all 47 vice ministers from the old regime, regardless of competence, sent a chill through the bureaucracy. Many government workers idle at their desks, worrying who will be next.

A similar message was delivered to the intelligentsia when a top government official addressing graduation ceremonies berated the university community for ostensibly supporting the Mengistu regime. Hundreds of students walked out.

"They are labeling an entire class as guilty by association," complained Prof. Mesfin Wolde-Mariam, a frequent government critic.

Despite such grievances, however, many moderate Ethiopians say the Democratic Front is the country's only and, perhaps, last hope.

Eshetu Chole, an economics professor, told a conference on economic policy that further delays in implementing reforms would be "suicidal." But he also warned that succumbing to "the factional interests of the day" would guarantee chaos.

In 1974, when Mengistu overthrew emperor Haile Selassie, "we were given a unique opportunity to construct a just society," Eshetu said. "We wasted that valuable opportunity. Now in a rare instance of generosity, history has given the Ethiopian people another opportunity.

"If we squander a second opportunity, we will never be forgiven by posterity."