South Yemen SANHA

"They will either shoot now or Sanha Radio will announce that a Russian commander was inspecting our front-line positions," said Mohammed Jabri, half seriously, "but we won't be shooting back." It did not look as though they would.

He was the commander of a company of some 15 men, half of them in ragged uniforms, half in the traditional skirt and turban of the Yemeni mountaineer. They were armed with nothing more than rifles. They were all lethargic, all recumbent, their cheeks bulging with qat, the mild narcotic herb that flourishes on these high green plateaus.

We were at Sanha, a little hilltop dominated by the old fort so typical of a land where for centuries, tribal warfare has been a way of life. A mile or so away, across the plain, was the town of Qaataba, North Yemen, and as we made a quick foray into no man's land, it was the enemy forces dug in there who would supposedly take me for a Soviet.

I was - so many guides kept reminding me - the first journalist privileged to visit these parts. It had certainly been a hard-won privilege.

South Yemen is such a security conscious country that it took no less than the new president himself, Ali Nasser Mohammed, to acquiesce in it. It had also been an arduous business getting there. Not far out of Aden, the road takes you along a not-so-dry riverbed, up the naked rock of a vertiginous gorge, then through the monsoon mudof the highland plateaus.

Not a shot was fired, and nothing was said on Sanha Radio. It is none the less axiomatic in North Yemen that its southern brethren have sold themselves out to the Soviets. They have become puppets in a grand design embracing Africa and the Middle East. They have turned their country into a springboard for Communist domination of the Arabian peninsula, with its oilfields and tanker routes to the West

THE-PROPAGANDA is often lurid. Thus, if one were to believe the Cairo-based publication, Voice of South Yemen, the country is nothing but a gigantic Soviet arsenal. The "red devils" have turned it into a "red bell," where all manner of immorality flourishes, where "semiliterate party cadres have opened taverns and bawdy houses right next to the mosques." There is no question that the North Yemenis, or rather, one should say, the Saudis and Egyptians who egg them on earnestly desire to see the end of this "bloody Marxist tyranny."

That is why, at their request, the Arab League, or what is left of it, has subjected South Yemen to a boycott which - apart from certain anornalies such as the continued presence of a Saudi embassy - is almost as severe as the Arab boycott of Israel. (That Aden apparently stage-managed the spectacular assassination in June of the North Yemeni president, Col. Ahmad Gashmi, was probably little more than a pretext for what was coming anyway.) It is also why, according to the South Yemenis, their neighbors are mobilizing troops all along the frontiers, from the Red Sea to the Empty Quarter deep inside Saudi Arabia.

There have been no clashes yet, but, according to Jabri, the northern troop concentrations which he showed me at Qaataba - and which he estimated at 1,200 men with tanks, mortars, and artillery - are already greater than those of September 1972, when the Arab League had to intervene to stop skirmishing and sabotage from degenerating into outright war.

THAT IS BY no means to say however, that South Yemen's ruling National Liberation Front does not consider itself a threat to its neighbors. The South Yemeni leaders are militants of the Marxist-Leninist faith, and the threat they present is a long term one, ideological, political cultural. In their view they are the most advanced political order not merely in their immediate environment still sunk in tribal, obscurantist reaction - but in the entire Arab world.

They are dauntlessly breaking ground where other "revolutionary Arab regimes, after initial strides in the right direction, have all ultimately feared to tread. In effect, that are - though they do not use the word - the first Communist regime in the Arab world.

A portrait of Lenin on his wall.Arabic translations of Soviet works lining his bookshelves. Salih Hassan, political commissar of the important provincial town of Zingibar, explained where even a great leader such as President Nasser had gone astray. He had failed to get beyond the "national democratic" phase of his bourgeois revolution, with its loose alliance of class interests, failed to move on to a fully fledged "scientific socialism" under the auspices of a proper "vanguard party" composed exclusively of peasants and workers. Revisionism inevitably set in, and, under Sadat, the fuedalists and capitalists are back in strength.

Yet South Yemen itself has only just managed to escape this danger. The recent power struggle was that critical watershed when the regime had either to retreat into the conventional pattern of Arab socialism as practiced in Egypt, Syria or Iraq, or go forward to the higher form of socialism as practiced in the Eastern bloc.

IN THE EVENT, it went forward. Abdul Fattah Ismail, the NLF secretary general, triumphed over President Salim Rubaya Ali, "organizational legitimacy" of the collective leadership over the "individualism" of a "deviationist clique."

It might easily have gone the other way, with Zingibar as the decisive battleground. For Zingibar was the home town of the late president. From there he might have gathered loyalist forces for a march on the capital. He was more popular than Abdul Fattah Ismail and the faceless party machine. He was thought to represent "Bedouin Socialism" with a human face, to be more flexible and realistic. He was readier for compromise with conservative neighbors - compromise which held out the prospect of economic and political liberalization and injections of the desperately needed cash that hardline Marxism scared off.

For 24 hours, on June 26, the country stood on the brink of civil war. At least two factors prevented it. One was the swift intervention of the air force against the presidential palace. Rubaya Ali was unable to escape and rally his supporters, or simply to demonstrate that he was still alive. The other factor was his opponents' much superior organization.

In spite of his greater personal appeal, they had been relentlessly undermining his power base within the government which originally lay mainly with the army. But the party outflanked him with the development of a people's militia, claimed to be a hundred thousand strong, and therefore three or four times the size of the army. Its core consists of full-time party cadres. Its rank and file are part-time volunteers.

IT WAS THE MILITIA that led the party assault all over the country. "We had 23 martyrs," said Muhsin Hussein, a 26-year-old commander in the Zingibar district. "While we killed 63 of Rubaya Ali's men" - whom he described, in the approved formula, as a mixture of "tribalists," dismissed army officers and mercenaries - "the moment his execution was anounced they all dropped their arms.

"With the victory of "organizational legitimacy," the way is now being cleared for the consolidation of the new order. Ali "deviationists" are being systematically purged. The party newspaper, October Fourteen, carries lists of them. The word, liquidation, sometimes creeps in. Its precise meaning is left to the imagination.

The driving force behind the new order will be the much-vaunted "new model vanguard party" due to come into being at the NLF congress this month. The qualified personnel are plentifully available. South Yemen's new university may be a rudimentary affair, but the Higher College for Scientific Socialism has already turned out 3,000 graduates - not to mention hundreds of others trained in the Eastern bloc.

ABDUL FATTAH ISMAIL, has long been seen - he barely hides it himself - as Moscow's man and his triumph will lock the quarter which, given an increasingly hostile environment, is its only reliable protector. For its part, the Soviet Union, having suffered so many setbacks in the rest of the Arab world, will presumably go to considerable lengths to preserve so loyal a protege.

It is improbable - though widely believed - that it was Soviet pilots who bombarded President Rubaya Ali's palace, but the Soviets and their allies are now so entrenched in the organs of power that, in all but the most direct, operational sense, they played a key role in ensuring the victory of their man. It is Soviets who trains the army, Cubans the militia, East Germans the much-feared security services.

OFFICIALS HOTLY DENY that they have permitted the establishment of Soviet bases on their territory. Aden airport is a staging post on the way to Africa, and Soviet warships take aboard fuel and food at the port. That is all, they say. "We do not call Saudi Arabia the satellite of a foreign power because of all its American experts, or Djibouti because of its French troops," said President Ali Nasser Mohammed.

For the more sober of the government's enemies, however, it is the potential rather than the reality, which counts. "There is no need to exaggerate," says the North Yemeni foreign minister, Abdullah Asmaj. "The Soviet Union does not need bases, but it has achieved such influence in South Yemen that it can be turned into the Cuba of the Arab world the moment the two parties decide."

The more the Soviets deepen their foothold in the Arabian Peninsula, the more the Saudis will work for the removal of this hostile intrusion in their own backyard. Inevitably, it is North Yemen that will bear the brunt of the struggle.