When shadowy commander Igor Strelkov appeared before the cameras recently in green combat fatigues and a clipped mustache, he did more than reveal the face of the insurgency rocking eastern Ukraine. He strengthened the case that Russia is behind the turmoil.
The commander did not address Ukraine and European Union assertions that he is a Russian intelligence officer. But he told journalists that he and his men entered Ukraine from Crimea, which Russia annexed in March after an insurgency that Russian President Vladimir Putin now admits involved Russian troops.
Strelkov's assertion that many of the insurgents are not locals undermines rebel claims that the insurgency is a spontaneous uprising, rather than a coordinated operation backed by outside forces.
"The militia is of course strongly sprinkled with volunteers from other regions," Strelkov said in a taped interview with Russian tabloid Komsomolskaya Pravda. He estimated that a third of the fighters are not Ukrainian. He backtracked Tuesday in an interview with Russian TV, claiming 90 percent of the militiamen were Ukrainian.
The EU on Tuesday included Strelkov among 15 new people targeted by sanctions. EU documents identify him as a member of the Russian military intelligence agency GRU, as do Ukrainian authorities. The commander himself was cryptic about his origins in the weekend interview.
In Moscow, a flurry of drama surrounded Strelkov's emergence, as camera crews swarmed around an apartment building that Ukrainian TV reported to be home to his mother. Neighbors told The Associated Press that a "fancy black car" had turned up Tuesday morning to whisk the woman away.
Equally murky are the origins of Strelkov's insurgents, their operations and their weapons. They have proven themselves to be ruthless and effective, running their campaign with unerring foreknowledge of Ukrainian security operations.
Strelkov said his forces obtained their weapons partly from police buildings they had taken over, adding that his men also took arms and vehicles from Ukrainian forces they fought when they entered eastern Ukraine last month.
"Russia so far hasn't supplied us with a single machine gun or bullet," he said.
It wasn't clear why Strelkov has chosen to go public now.
The insurgents are seeking more autonomy from Kiev - possibly even independence or annexation by Russia. Ukraine's acting government and the West have accused Moscow of orchestrating the unrest, which they fear could be used as a pretext for a Russian invasion.
The belief that the Kremlin is directing the insurgents - whose mysterious origins and green fatigues have won them the moniker "little green men" - gained credence when Putin last month dropped his denials that the Russian army had been deployed in Crimea during the uprising in that region.
But there are differences between that situation and eastern Ukraine. The pro-Russian fighters here are substantially less numerous than they were in Crimea. And they fall into two broad categories: men in uniform who have the skills of professional soldiers, and less-organized local militiamen.
The former, comprised of men dressed in balaclavas and a variety of military-style fatigues without insignia, have been deployed in rapid seizures of government offices. On Monday, a gang of about 15 such men carrying Kalashnikovs took over a building housing the city hall and city council in Kostyantynivka, 160 kilometers (100 miles) west of the Russian border. At least one was carrying a rocket-propelled grenade launcher.
Strelkov said his own militia force is made up of battle-hardened fighters: "Many are Ukrainian citizens who have fought in the ranks of the Russian armed forces - in Chechnya and Central Asia. There are also those who fought in Iraq and Yugoslavia in the Ukrainian army. There are even those who have managed to be in Syria."
A clearly less professional crew patrols checkpoints in and around the city of Slovyansk, the insurgent headquarters. Typically dressed in civilian clothing, these local men are mostly armed with simpler weapons. Some carry hunting guns; others just have sticks.
In one of the rare instances in which Ukrainian government troops moved in on the insurgents - at a checkpoint at the northern entrance to Slovyansk - the people defending the position dispersed quickly.
But these locals can also be effective: Mobs of stick-wielding men and fiery civilian crowds have played important roles in seizing government offices and, in one case, snatching armored vehicles from Ukrainian troops.
Estimates of the insurgents' numbers are hard to come by, but a variety of witness accounts suggest the low hundreds.
Harder to pin down is a clear link to Russia. Putin denies his forces are in eastern Ukraine and his foreign ministry calls such claims "flimsy insinuations."
But several journalists have reported militiamen letting slip that they are Russian citizens, and U.S. and NATO officials insist there is strong evidence linking events in eastern Ukraine to Russia.
And the eerie skill with which the green men anticipate Ukraine's every security move offers strong circumstantial evidence of Russian involvement.
On April 13, Ukrainian special forces poised to launch a strike on the town of Slovyansk were preemptively attacked by a handful of suspected pro-Russian troops. Then, this past weekend, three Ukrainian special services agents were kidnapped and spirited away to Slovyansk, where they were presented to Russian journalists with signs of heavy beatings.
As the reporters harangued the bloodied men, stripped of their trousers, Strelkov crowed about his ability to outfox his opponents.
Both Western and Ukrainian experts say the events suggest that Ukrainian security services have been infiltrated by Russian intelligence.
"We have our own agents who have been recruited, who are working for the adversary," said Vasil Krutov, head of Ukraine's anti-terrorist center.
U.S. Air Force Gen. Philip Breedlove, NATO's supreme commander in Europe, argues that the conclusion to be drawn from observations on the ground is inescapable.
"What is happening in eastern Ukraine is a military operation that is well-planned and organized," Breedlove wrote on the NATO website, "and we assess that it is being carried out at the direction of Russia."