BELGRADE, Yugoslavia -- It was like a scene from Yugoslavia's bloody past.
Black flags fluttered in the breeze in the shadow of the dark mountains of Ravna Gora. Hundreds of men in old-fashioned beards and Serbian hats whooped and fired pistols and automatic weapons in the air.
Their rhythmic chanting -- "Kill Ustashi" and "We want war!" -- turned to thunderous cheering as their leader, "Red Duke" Vojislav Seselj, arrived to promote Chetnik commandos who had killed Croats.
History is threatening to repeat itself and engulf central Yugoslavia in ethnic civil war of a type Europe thought it had seen the last of -- a war with the Red Duke's Chetniks and similar exponents of violent nationalism at its heart.
Last week, Mr. Seselj traded his role as outside provocateur for a place in the center stage of Serbian politics when he took a seat in the republic's Parliament. He has openly boasted that his Chetniks have provoked battles in Croatia in which more people have died over the past two months than died in the federal army's assault on Slovenia.
In apparent collaboration with Serbia's mercurial President Slobodan Milosevic, the Red Duke apparently has the role of setting the nationalist tone and destroying moderate opinion in Parliament and society as Serbia prepares for war against neighboring Croatia. The objective would be to seize back land in Croatia historically claimed by Serbia and presently inhabited by 700,000 Serbs. The republic also has claims on Serbian-inhabited land in another central republic, Bosnia and Herzegovina.
Mr. Seselj's impact in Parliament was immediate. He called for defeatists to be shot. He warned Yugoslavia's Muslims not to side with the Croats. He said moderate Prime Minister Ante Markovic should be arrested. He said the army should extract itself from Slovenia and the Slovenes should quickly become independent. Otherwise, he declared, "we should bomb Ljubljana," the Slovene capital.
Not an aristocrat, he professed himself proud of his nickname and considered the Croats' hatred of him to be honor.
His wild and heated debut last Tuesday compelled adjournment as screaming and scuffles broke out among deputies. Mr. Seselj's side and tone were immediately taken by deputies from Mr. Milosevic's ruling Socialist Party.
As Mr. Seselj was radicalizing Parliament, Croatia said it was about to release the photographs and identities of the first Chetniks it had captured. It charged that hundreds of the armed Serb guerrillas had crossed the Danube into Croatia over the past two weeks and had taken up position inside Serbian villages in Eastern Slavonia.
The problem is that in a highly inflamed atmosphere any Serb entering Croatia is regarded as a Chetnik, and Serbian villagers who have gotten arms to defend their homes are described as terrorists. Most women and children have been evacuated from the villages, leaving their armed menfolk and the Chetnik reinforcements behind.
Indeed, battles between Croatian militia and the armed Serbs broke out almost every night last week, with scores of deaths and casualties.
The number of men under the Duke's command is a secret -- estimates range from hundreds to tens of thousands. Chetnik enlistment centers have been set up throughout Serbia -- even in Belgrade's fashionable Knez Mihailo Street, where a Chetnik folk singer plays the accordion and croons, "I would lay down my life for the Serbs of the Krajina [a Serb enclave in Croatia]."
The main distinguishing Chetnik feature is a bushy beard and long hair -- supplemented at ceremonies by old Serbian hats and royalist badges, symbols all used deliberately to rekindle nationalist passions.
For the Chetnik is no modern phenomenon. Chetniks were paramilitary groups that organized shortly after Serbia won autonomy from Turkey at the beginning of the 19th century. They operated on Serb lands controlled by Turkey and were secretly armed and supplied by the Serbian army.
With the creation of Yugoslavia in 1918, there was no longer a need for the Chetniks because the king of Serbia extended his rule not only over all Serbian lands but also over Croatia and Slovenia. The Chetniks were revived in 1941, when Nazi Germany attacked Yugoslavia and defeated the Yugoslav army. Serbian officers and soldiers led by Col. Draza Mihajlovic withdrew to the mountains to mount what was the first armed resistance to the Nazis in occupied Europe. As such they were an important symbol for Western propagandists.
But soon the Chetniks were involved in a mortal struggle against Croatian fascists known as Ustashi, the storm troopers of a Croatian state set up by Hitler. Marshal Tito, then a Communist partisan, outmaneuvered Mihajlovic and the five other "dukes," as the Chetnik leaders were known. Mihajlovic's objective was more a preservation of the Serb population, as opposed to Tito's all-out struggle against the Germans. Western support switched Tito. Mihajlovic and most Chetnik leaders were captured and executed at the end of the war.
Last year, Mr. Seselj -- a former anti-Tito dissident -- traveled to the United States to see one of the surviving Chetnik dukes, Momcilo Dujic, who has been living in exile since 1945. The patriarch conferred the title of duke on Mr. Seselj. The addition of "Red" came from opponents who suspected him of working closely with Mr. Milosevic, a Communist who now calls himself a socialist.
When Mr. Seselj returned from the United States, he organized the Chetnik revival -- though he was refused permission to register a Chetnik party for the first Serbian multiparty parliamentary elections. He did register himself as a candidate for president, however, and came in fourth in a field of 32 -- a reflection of the passions he had aroused.
Mr. Milosevic and Serbian officials over the past week have set Serbia's course.
They say that Slovenia and Croatia should be allowed to go free from Yugoslavia but those regions that wish to remain a part of Yugoslavia should be allowed to do so, with the army stationed on their territory. The term was a clear reference to the Serbian enclaves in Croatia where Serbs want to join with Serbia.