LJUBLJANA, Yugoslavia -- The platoon of Slovenian police reservists at the Ljubelj border crossing looked like a nervous lot as their commandant raised the white, red and blue Slovenian flag above the customs house June 26.
A half-mile down the winding mountain road, at the Marshal Tito army post, a detachment of federal Yugoslav People's Army troops waited with tanks and armored cars.
The Slovenians, well-equipped with bulletproof vests and blue-gray uniforms, had only high-powered rifles, Kalashnikov submachine guns and a few shoulder-fired anti-tank missiles.
"A firefight will not be fun," said a beefy 22-year-old police reservist who spoke fluent English.
Before dawn the next day, the federal army attacked Ljubelj and about 45 other border crossings with tanks and armored personnel carriers in an effort to restore federal control over the breakaway republic.
But within hours, Soviet-designed T-64 and T-72 tanks lay burning in the Alpine passes, a half-dozen federal troops lay dead and the reputation and honor of the Yugoslav People's Army lay in tatters.
How did a small alpine republic of some 2 million relatively prosperous Slovenian burghers defeat what was once regarded as the finest professional army in Communist Europe?
The Slovenians' response was a superbly coordinated combination of civil defense and guerrilla warfare, carried out by Slovenia's police, police reservists and the territorial defense militia, similar to U.S. national guard units.
At 4 a.m. June 27, as the first reports of federal troop movements arrived at Slovenian defense headquarters, truck and bus drivers and civil defense officials were awakened and told to take their vehicles to preselected crossroads.
When federal armored columns stopped to clear the roadblocks, squads of Slovenian police and militia scrambled down the hillsides, fired anti-tank weapons and melted away into the forest.
"The genius of it is that to clear the roadblocks they have to stop, and that's when we get them," said a Slovenian militia officer manning a roadblock on the Ljubljana-Zagreb highway.
In part, the federal troops have been hampered by their own orders.
"We could have cleared all the roadblocks, but our orders were to use minimal force," said Maj. Radomir Kostic, deputy commandant of the Vrhnika armored barracks.
"The Slovene doctrine is very close to that of the Swiss," explained Anton Bebler, one of the architects of Slovenia's defense.
"The whole idea was to use guerrilla warfare. Avoid large clashes; avoid battles. Block, stop and exhaust the enemy. Demoralize them," said Mr. Bebler, a professor of military history at Ljubljana University.
The army's radio and telecommunications links with headquarters were jammed or cut, supplies were blocked and troops were forced into constant contact with the hostile civilian population. Western jamming equipment and anti-tank mines played a key part.
Training was also vital. Members of the Slovenian militia are former federal army draftees who receive an additional two weeks of guerrilla warfare training each year.
The Slovenian forces have only 300 professionals, but already 30,000 of a total of 78,000 Slovenian reservists have been mobilized.
The federal army only sent out a small portion of its 4,000 to 5,000 troops stationed in Slovenia before barracks were barricaded.
The Slovenians have a range of light infantry weapons, including shoulder-mounted anti-aircraft and anti-tank weapons, 82mm mine throwers and lightweight anti-tank recoilless rifles that can be carried across the mountains on horseback.
Using these weapons and guerrilla tactics, the Slovenians can fight a hit-and-run war of attrition like the one their parents waged as Communist partisans against the occupying Nazis in World War II.
And the plan has worked to perfection. By the end of the first day of fighting, dozens of federal army troops had surrendered.
The army has contributed to its own defeat. Raw recruits, most barely 18 years old, far from their homes in the southern republics of Kosovo and Macedonia, manned many vehicles.
The army moved in without any air cover and sent out antiquated equipment. Of 40 tanks sent to take the Ljubljana airport, the Slovenians estimate that more than half broke down from mechanical problems.