If yesterday you hated me, today you cannot avoid the love that binds you to me and me to you," Prime Minister Robert Mugabe told his countrymen in 1980, when independence ended a bitter, seven-year civil war. "The wrongs of the past must now stand forgiven and forgotten."

At a rally three weeks ago, Mugabe had a different message for Zimbabweans. "If you support the dissidents," he said, "people are going to be killed, because this is war. Don't cry if your relatives are killed."

The contrast between those two speeches is a good measure of how the atmosphere in Africa's youngest nation has changed three years after the world applauded its hard-won independence.

With Mugabe calling for reconciliation after the civil war, Zimbabwe was born in a mood of euphoria in 1980.

As Africa's newest nation, Zimbabwe represented the continent's hope for a successful multiracial democracy, incorporating a mixed economy. It was to refute white-controlled South Africa's argument that black rule meant bad rule.

South Africa's defense of its racist policy is as questionable as ever, but few neutral observers would hold up Zimbabwe today as a shining light after weeks of Army brutalities against civilians in Matabeleland, the tribal stronghold of opposition leader Joshua Nkomo.

To some, the dream has faded and Zimbabwe is becoming "just another African country."

The promise remains, however, since Zimbabwe still has a lot going for it despite problems common to many African countries--drought, recession and low world prices for commodities.

Outside of Matabeleland, in the southwest, the country is peaceful under black-majority rule.

There is still respected management of the financial sector, a well-developed economic and agricultural infrastructure and a nucleus of experienced whites and university-educated blacks, attributes that are rare in Africa.

Today, however, Zimbabwe is an embattled country threatened by what it regards as internal and external enemies.

The threat is real: hundreds of armed dissidents, mainly Army deserters who were formerly guerrillas loyal to Nkomo, have killed almost 150 civilians, robbed and terrorized many more and destroyed government development projects in Matabeleland since Mugabe fired Nkomo from the Cabinet last year.

In response, the prime minister unleashed the Army, mainly using troops from his majority Shona tribe. Seeking to wipe out support for the dissidents among the Ndebele tribal minority loyal to Nkomo, the soldiers killed hundreds of civilians.

In such an atmosphere there seems to be little room for political compromise, causing growing concern that Zimbabwe is locked on a confrontation course that could eventually lead it down the familiar African path of tribal hostilities and autocratic rule.

With powerful, hostile South Africa as a neighbor, there is the potential for the kind of conflict that is currently destabilizing Angola, Mozambique and Lesotho.

Perhaps no country could live up to the euphoria that surrounded Zimbabwe's birth. Now the Matabeleland killings could turn out to be a watershed in the image Zimbabwe conveys to the outside world.

In response to foreign and limited domestic criticism of the Army operations, the government has hit back hard, saying the offensive will continue until all dissidents are wiped out.

Hardly a day goes by without Mugabe or some other senior official attacking Nkomo--who is in self-exile in London--his party, South Africa or the foreign press for its criticism. Neither churches, nongovernment relief organizations nor sometimes even foreign governments are spared.

It is chillingly reminiscent of how South Africa, Zimbabwe's bete noir, reacts to criticism: hunker down and lash out at the foe.

Ever so occasionally, pained private conversations here touch on the point that indeed, Zimbabwe "is just another African country" and as such will have to go through all the trials and tribulations of the rest of the continent.

Racists, who still abound in this country, always believed that, but the remarks are now coming, reluctantly, from thoughtful people, both black and white, who are striving for racial harmony.

"We were misled to think we were a different kind of African country," said an official who spent all of his adult years in the West before returning to Zimbabwe at independence. "There is no escaping it. This tribalism is our inheritance," he said, and then quickly blamed colonialism for the legacy.

Actually, hostility between the majority Shonas and the Ndebeles predates the arrival of the whites in the country in 1890, but the colonial regime did pit one tribe against the other.

In Kenya, which faced a similar tribal situation, Jomo Kenyatta, the first president, eliminated his political rival from an opposing tribe but was careful not to unleash ethnic strife.

Mugabe, whose image in Africa so far ranks with Kenyatta, may not be able to steer such a fine line. It took Western Europe 500 years and numerous bloody wars to overcome the worst vestiges of tribalism, which come in the form of nationalism on the continent, so perhaps African tribalism needs to be regarded in that time frame.

"We are becoming just another African country," said a business executive and member of Nkomo's party who maintains close ties to government officials.

"Once you are labeled with Idi Amin and [Jean-Bedel]Bokassa," he said, in a reference to the former dictators of Uganda and the Central African Republic, "you've had it with friends" in the West.

He stopped well short of putting Zimbabwe in that category, but a year ago nobody would have thought of mentioning Zimbabwe in such a context.

"I feel we have entered the African groove," he said. "Very often when you enter it you don't get out."

"We are making the same mistakes as other African countries," rather than learning from their experiences, he added and listed "poor economic policy, tribal confrontation and not caring about human rights or international opinion."

The situation could have been much worse, he added, since at independence the country inherited three warring armies. He praised Mugabe for integrating the armies, but said without unifying the parties it was like "uniting the legs and letting the heads go in separate directions."

A Zimbabwean intellectual said sadly, "I have to accept that the image of Zimbabwe has been permanently damaged" by the events in Matabeleland.

Like many other Shonas, however, he laid most of the blame on Nkomo, saying he never accepted Mugabe's 1980 election victory.

"To Nkomo, power is the most important thing in his whole life," he said. "While he has life he'll fight for power."

Even though the level of violence employed by the Army seems to have tapered off in recent weeks, the controversy has entered a different phase, centering on government reaction to criticism over the Army's tactics.

Stressing Zimbabwe's independence, Mugabe has made it clear that only the government will investigate the events in Matabeleland and that outside criticism will be dismissed.

Questioned about the investigation, which has been promised since January, a government spokesman was unable to say who was heading the probe, who would receive the report, what progress was being made or anything else about the inquiry. Presumably the Army is being asked to investigate itself.

"There are 150 independent countries in the world," said a western diplomat, despairing at the Zimbabwean attitude. "Many listen to criticism and are willing to compromise." On this issue, he added, the government does not care about international opinion and has no credibility overseas.

Diplomats are careful to point out that the government was justified in taking military action against the dissidents and, in fact, was in danger of losing public support until the Army offensive began in January. It is the violence against civilians that they complain about.

Mugabe has criticized the lack of similar outrage against the acts of the dissidents. Ironically, his problem is the same as that of the white government that fought his guerrillas: armies are supposed to protect the populace, not adopt the same tactics as insurgents.

Most embassies have made private representations to the government but have not gone public. The major exception is Sweden, which has suspended consideration of aid for the next fiscal year until it receives clarification from the government on the situation in Matabeleland.

A State Department spokesman cautiously said, "We believe the Army has employed methods which raise serious questions about prospects for peace and stability" in Zimbabwe.

U.S. officials say it will be difficult to get congressional approval for $75 million in aid programmed by the administraton for fiscal 1984. Sen. Jesse Helms (R-N.C.), a long-time foe of Mugabe, submitted 25 critical questions to Chester Crocker, assistant secretary of state for African affairs, in connection with the proposed aid.

For most western governments and relief organizations, however, Zimbabwe provides a rare opportunity for programs to achieve quick results. The consensus is that Zimbabwe is too important to pull out.

"Either you stay and influence the situation or pull the rug out and go," said a diplomat whose country is heavily committed to Zimbabwe. "We're not about to go."

Another diplomat agreed but said there is a residue of bad feeling. Most governments could not remain quiet if there was another round of Army violence against civilians, he added.

Slowly, as the situation has calmed somewhat, there have been occasional pleas for reason in the government-influenced press despite the overall harsh attitude toward any criticism.

An editorial in The Sunday Mail newspaper said, "We overreact to our problems, no matter how trivial they may be. We become hysterical; we scream and squeal."

Since the hostilities, Mugabe has spurned any dealings with Nkomo and his party, which he says is seeking to overthrow the government. Nkomo denies the charge and disavows any connection with the dissidents, but Mugabe said recently unless the party disarms the dissidents "we will disarm them as a party."

That was taken as a strong hint that he would ban Nkomo's Zimbabwe African People's Union party, which would propel the country toward the one-party state the prime minister favors.

Nkomo has fled into exile in London, saying Mugabe ordered him killed. The prime minister has denied the charge.

As a guerrilla leader and a politician, Mugabe has only occasionally shown willingness to compromise from a position of strength once he has set a course. The reconciliation policy and bringing Nkomo into his Cabinet are exceptions.

Having the upper hand, there seems to be little likelihood that Mugabe will work out a compromise with Nkomo and his party. Surrender or war appear to be the only options for "the father of Zimbabwe."

There is no doubt, a diplomat said, "in the short term the government can win. In the long run they can't," he added, saying there must be a political settlement.

Officials place great stock in a political offensive that Mugabe's Zimbabwe African National Union party is mounting in Matabeleland. The message basically is: drop ZAPU and join hands with the government if you want to survive.

Government officials assert that thousands of ZAPU members are turning in their party cards for ZANU membership in response to the drive.

A disgruntled ZAPU official, maintaining he was forced to attend such a rally in the bush, said, "What can we do? If they say join ZANU, we'll join. It's unfair. They're forcing us."

The effect, a despairing priest in Bulawayo said, "will be more bitterness, more hatred, more violence. People are inclined to take revenge. That means there will be no peace."