"Ziegler, Stephen," read the heading of the death notice inserted by his army friends the other day in the Rhodesia Herald. "Ziegs, cheers my buddy, you gave your life for Rhodesia (Not Zimbabwe). Let it not be in vain."

That sentiment could well serve as an epitaph for white Rhodesia. Barring unforeseen hitches, undisputed white rule seems to be playing out its time now that an agreement between Prime Minister Ian Smith and three locally based African leaders appears to be within reach to bring about black majority rule in a country to be renamed Zimbabwe.

In more normal times, that would count as no mean accomplishment. Less than a year ago Smith was reassuring the country's quarter million whites that they should have no fears about any notion that there would be black rule.

What brought about Smith's change of heart is clear: a calamitous economic situation, soaring war costs, an accelerating white exodus and stepped up guerrilla activities.

But little else is as clear. Pessimists are less impressed by the prospect of quick internal agreement, the officially proclaimed key to a return to peace and prosperity, than by their fears of a resulting cataclysmic civil war between black factions.

Part of the problem is Rhodesia-s isolation.

Geographically landlocked, Rhodesia had become legendary for its insulariyt even before Smith's declaration of independence from Britain in 1965 cut it off further from the rest of the world.

Blacks and whites in their separate ways tend to live in a world of their own dreams, or nightmares. It is a perhaps understandable state of mind for men and women now faced with so many political and military unknowns.

A certain helplessness and anger with the British and Americans - who, it is felt, should be helping - pervades much of the thinking of Smith and his black allies. Feeding those frustrations is the knowledge that the success of any internal deal depends on outsiders, ranging from South Africa and the frontline black presidents to the Soviets and Cubans, over whom they have no control.

Given this atmosphere, there is a tendency toward wish fulfillment - turning Smith's vague suggestions into accomplished fact.

For example, many whites have convinced themselves that the guerrilla war will stop with the announcement of an internal agreement. Why? Because they are sure that Mozambique and Zambia from where the guerrillas operate, will back the internal settlement and shut down their bases.

Pressed to explain why, their response usually revolves around those two countries' dire economic problems, which will convince them that peace will mean reopened borders and prosperity.

To date, there is no convincing evidence to this effect. Rather, the whole proposition reflects many whites grasping at straws. Even the Rhodesian government has warned of an upsurged of guerrilla activity following any internal settlement.

Nor are black leaders immune from temptations to see an easy way out. The Rev. Ndabaningi Sithole, of the African National Council wing bearing his name, is on record as promising that the guerrilla war will stop "at the snap of a finger" with the proclamation of a cease-fire, which is a key part of an internal agreement.

Sithole claims to control the guerrillas inside the country under the Zimbabwe African National Union banner. His critics claim his only troops are a handful of army deserters.

Blacks who have talked to guerrillas say that the fighters' loyalty to National Union Leader Robert Mugabe is nominal at best and that they say he could be replaced by any of a number of a rival warlords.

Furthermore, the guerrillas are said to denounce not only the whites, but also Joshua Nkomo, Mugabe's co-leader of the externally based and tenuous Patriotic Front, which is supposed to be coordinating the two rival armies.

Guerrillas from each group are already said to be infiltrating into the tribal areas of the other.

Indeed it was the threat of the guerrillas that motivated the odd alliance between Smith and African nationalists at the internal settlement talks; that plus the black leaders' political ambitions.

If there is any hope for success, it ities with Smith's increasingly black army - and the backbone of an efficient white-run civil service.

Even so there are many difficult questions.

What makes the internal leaders so sure the guerrillas will lay down their arms simply because the black goal of majority rule has been achieved?

And, as the Ziegler death notice so ominously suggested, will the whites, who make up the cutting edge of the army, continue to fight for a black government?

Some observers are convinced that the army maintains its edge now thanks largely to some 1,500 foreign white volunteers, who might also not want to get caught up in a black versus black war.

In the event of an internal settlement, would the army be able to handle what promises to become an increasingly serious second front with Nkomo sending thousands of reputedly well trained guerrillas into Rhodesia? The security forces already have been badly stretched and only a few hundred of Nkomo's men are believed inside the country compared to between 3,500 to 9,500 Mugabe's guerrillas.

All this would appear to give a somewhat precarious underpinning to any one-year interim government leading up to elections implementing black rule.

Any prediction of the possible showing of the various politicians in such elections is difficult - if only because it seems doubtful that either Nkomo or Mugabe are prepared to return.

If they stay out, the ability of the guerrillas to intimidate voters and disrupt the elections could deprive Smith and his allies of the proof of freely expressed democratic will that Britain, the United States and much of the world would require to accept the internal settlement.

Even the drawing power of front-running Bishop Abel Muzorewa, of the United African National Council and one of the internal black leaders involved in the agreement may had been damaged by his inconsistent behaviour. He first stood up to Smith, much to his followers' delight, then inexplicably capitulated on the key issue of representation for the whites.

Smith once said Muzorewa was "not very sound or consistent, I'm afraid, when he starts talking politics. He's far better when he sticks to the religious field."

Lagging far behind Muzorewa is Sithole, a once powerful leader whose ambition has hurt him in black eyes. Nor have blacks forgotten the political wars between Sithole's followers and Nkomo's in 1963 and 1964 that included hundreds of acts of violence that were used by the government as grounds for detaining all top African political leaders for 10 years.

As for Jeremiah Chirau, a traditional chief involved in the internal settlement, among his most outspoken supporters are whites who do not seem to have understood the mass appeal of black nationalism.

Chirau is denigrated by even his fellow blacks as an extension of Smith and he has served as a window dressing non-voting cabinet minister in Smith governments. He has said that "the thinking African appreciates the value of European leadership."

Asked how many seats Chirau's well-heeled Zimbabwe United Peoples Organization could hope to win in elections, one chief replied: "His own."

In private many blacks and whites wonder despondently about the future no matter what their optimistic public posture.

Random white comments range from, "Every time there's a new negotiation the terms get worse" to "The more you look at the details the more unhappy you get."

Blacks are worried about the lack of clear-cut black leadership, a failing Smith has exploited to stay in power in the past.

One middle-aged black politician expressed his concern that in the face of mounting violence, "our generation's views will be irrelevant."

Having spent 10 years in jail for his political activities, he added "Despite everything I was not and am not anti-white. But these young men fighting are and they risk running the show."