Only about half of the two million people living in the former Yugoslav Republic of Macedonia are "true" Macedonians, and the arrival of hundreds of thousands of Albanian refugees threatens to change the demographic landscape radically. The need to survive in close relation to Serbia on one side and Greece on the other has created extraordinary tensions. PNS correspondent Thomas Goltz is the author of "Azerbaijan Diary: A Rogue Reporter's Adventures in an Oil-rich, War-torn, Post-Soviet Republic" (M.E. Sharpe, 1998). THIS IS THE FIRST OF A TWO PART SERIES BY GOLTZ.

SKOPJE, MACEDONIA -- The drone of the high-flying, invisible NATO planes in the skies above Skopje, the capital of the former Yugoslav republic of Macedonia, is a constant presence -- but almost never mentioned in polite company.

"We do our best to keep the war as far away as possible," said Slobodan ("no relation to Milosevic!") Ugrainovski, a businessman. "Let the refugees stay in their camps and let the NATO soldiers keep to their barracks, or at least out of sight."

Indeed, were it not for the hundreds of journalists and the planes, there is little sign of the war going on only some 20 miles away.

But the calm is misleading. The fragile, three-party coalition government trying to guide the tiny, multi-ethnic state through the current storm is in danger of collapse -- simply because of the crush of Kosovo Albanian refugees.

"The situation is incredibly fragile," said Zamir Dika, a member of parliament from the Albanian Democratic Party of Macedonia. "We know that the government is doing as little as possible for the refugees, but we cannot complain openly about that. It is time to dig in our own pockets and provide whatever aid we can."

According to U.N. estimates, fully half the 200,000 refugees from Kosovo who have come over the border are staying in private homes in mainly Albanian cities. They often arrive via a fleet of midnight taxis, called on cell phones.

The government has closed the frontier at least twice over the past two weeks, restricted the U.N. from setting up new camps or expanding old ones and is generally dragging its feet on every aspect of the refugee issue save one: dispatching as many refugees as possible to other destinations.

The reason is simple. Only half of Macedonia's two million citizens are actually Macedonians, that is, Orthodox Christians who are native speakers of a southern Slavic language (which is closer to Bulgarian than to Serbian). The other half of the population is a crazy-quilt of Serbs and Bulgarians, Greeks, Turks, Latin-speakers called Vlacs, Macedonian-speaking Muslims known as Goran and two distinct groups of "Gypsies," the Rom and a splinter group of conservative Muslims who sued for and were granted the special ethnic distinction of being "Egyptians" on the grounds that their ancestors followed the armies of Alexander the Great back to his native Macedonian from their homes on the banks of the Nile.

"Multi-ethnicity is the driving and defining characteristic of Macedonia," said Sasha Ordonovski, editor of a well-respected magazine. "Preserving and enhancing ethnic diversity is what makes us unique in the world -- but is also the root of the greatest danger to our survival as a state."

The main (perceived) danger comes from the one ethnic group not mentioned above: local Muslim Albanians. They are at least a quarter of the population, but their absolute numbers are a hotly contested issue -- mainly because the Macedonians of Macedonia fear they may be more.

"The fear is that if enough Kosovo Albanians remain in the country, the total number of Albanians might exceed that of the Macedonians themselves in a few years," said Liam McDowall, who is with a media-oriented NGO. "The whole reason for there being a Macedonia would thus be called into question."

The fear that Macedonia's existence is imperiled by the flood of unwanted Albanian guests, not to speak of the possibility of an expanded war fought on (or over) its territory, is at the root cause of the anti-NATO and anti-American sentiment sweeping across the land.

"I am not a Serb, or a lover of Serbs, but I will not be part of their destruction at the hands of a greedy, soulless superpower called America and the NATO alliance," said Dragadan Ivanovski, a bar owner. "If there is a call up and my son is told to bear arms against the Serbs, I will tell him to lay down his arms and go to jail for desertion."

All this has put President Kiro Gligirov in the impossible situation of insisting that NATO will not be allowed to use his country as a jump off point for any future ground war, while begging NATO for security guarantees in case Serbia should attempt to draw Macedonia further into the conflict.

Editor Ordonovski says "We have to be utterly realistic about our priorities." If, she argues, Albanian refugees threaten the state, and they are driven by the situation in Serbia and Kosovo, the only answer is ground war. "And to insure that the ground war be as successful as possible as quickly as possible, we absolutely must allow NATO to use Macedonia as a base. President Gligirov knows this, but he will still be shouting 'No ground war from Macedonia' even as the tanks are rumbling through the streets beneath his window."

As for the refugee Kosovar Albanians, their welcome even by their ethnic kin in Macedonia is starting to wear thin. One story making the rounds concerns a man from Tetova who, unable to continue to feed his 20 guests on his salary, informed the refugees that he was obliged to sell his car. One of the refugees told him he would be interested, if the price was right.