THERE ARE no coups here, no wars no political prisoners.

There are no riots, and crime is not rampant. The press, although government owned, is not censored. The people, if not wealthy, are not starving.

Until April of this year, there was not even an army.

There is, of course, political opposition the Marxist party that wants very much to throw the Western-leaning government out of office.

But the Marxists are operating at the polls instead of from the hills. They are not doing too well either. In a byelection in October, more than 1,500 votes were cast in a key district. The Marxist candidate got 27.

So much for the revolution.

This is Botswana, a country in the center of Southern Africa with an area of 220,000 square miles, making it about the size of either Texas or France.

With a population of slightly more than 750,000, Botswana is tied with Mauritania as the least densely populated nation on the African continent.

Perhaps more significantly, according to groups like Amnesty International, Botswana's open, multiparty political system ranks it along with tiny Gambia as one of the only two true democracies in Africa.

In the year of human rights, this gives Botswana a tremendous appeal for aid giving countries. This fiscal year, Botswana is getting $50 million in foreign aid.

While this may not sound like much, Botswana, because of its smaller population, finds itself well ahead of aid show cases such as Tanzania on a per capita basis.

"You can't give this country enough, its human rights record is so good," said a diplomat here.

Despite this, Botswana goes unnoticed. Correspondents and diplomats pass over, around and through Botswana on their way to southern Africa's trouble spots.

Few stop to see Botswana. Some have never heard of Gaborone - pronounced Hah-bohr-OH-nee - the capital.

Idi Amin gets attention. Botswana is ignored.

"Please say something about this country," pleads U.S. Ambassador Donald C. Morland.

INDEED, BOTSWANA deserves credit for being an oasis of stability in the middle of turbulent southern Africa.

To large extent, the country's political unity is traceable to the fact that Botswana, unlike many other African countries, is populated mainly by one group, the Tswana, who speak a commoun language, Setswana.

Even Botswana's democratic practices have tribal roots in the traditional tsurana kgotla, or elder's council, at which opposition is encouraged - indeed, expected - before a vote on any issue is taken.

Botwana's president is Sir Seretse Khama, grandson of the Tswana paramount chief who sought protectorate status from the British when he saw Boer and English settlers charging through the neighboring tribal lands that later became Rhodesia.

A soft-spoken, down-to-earth man who shuns publicity, Khama leads the Botswana Democratic Party, which holds 28 of the 32 elected seats in the National Assembly. His party's platform supports democracy, development , free enterprise and multiracialism.

From Gaborone, a city of 38,000 with the air of a prosperous Midwestern farming center, Khama administers a civil service of fewer than 10,000 that has not been accused of bribery, scandal or ineptitude - even by the opposition - since independence on Sept. 30, 1966.

WHAT PROBLEMS there are come from over the border.

A swelling refugee population pours in, mostly from Rhodesia but also from Namibia and South Africa. Even with aid from the U.N. High Commission for Refugees, the refugees strain the country, socially and economically.

In addition, as the Rhodesian war has intensified, it has slopped over Botswana's borders. Because guerrillas have tried to use Botswana as a base, Rhodesian troops have crossed into Botswana at least 30 times, damaging property, occasionally kidnapping suspects, and leaving behind an uncharacteristic bitterness among the Tswana and Matabele citizenry in the border areas.

Botswana reacted last April by creating a thousand-man army that does little more than patrol the border. Ostensibly, the army is supposed to keep out the Rhodesian troops of Prime Minister Ian Smith. Officials in Gaborone admit, however, that they find the best way to keep out the guerrillas they are chasing.

Considering Botswana's role as "front line state" that is supposed to be supporting the guerrillas, tha policy seems a bit of a contradiction. But then, so does much of Botswana's foreign policy.

While Khama is an outspoken opponent of neighboring South Africa's apartheid policies, Botswana carries on a flourishing trade with South Africa, depends on South African mines, and welcomes droves of South Africans who come on weekends to gamble in Gaborone's casino.

Botwana's economy, based on cattle exports and buoyed recently, by the mining of copper and diamonds, has remained stable despite Southern Africa's pervasive turmoil.

Perhaps the country's only major internal issue is who will succeed Khama, who has a heart condition and wears a pacemaker. But people here don't spend much time worrying about that.

A Gaborone journailst, asked what might happen if the president's health should fail, replied matter-of-factly, "I suppose another president will be elected".

it is reasonably safe toassume that in Botswana, that's they way it will work.