So far, the only solid fact, at least according to Estonia’s version of what happened in a thicket of pine trees and scrub on the border here with Russia, is that a well-trained and well-armed squad of Russian security operatives crossed into Estonia on Sept. 5 and grabbed Eston Kohver, a veteran officer in the Estonian Internal Security Service, known as KAPO.

Their movements masked by a volley of smoke and stun grenades, in the Estonians’ telling, the Russians dragged Mr. Kohver at gunpoint into Russia across the meandering and mostly unmarked line that separates the two countries.

The next time anyone in Estonia saw Mr. Kohver was when he appeared the following day on Russian television wearing handcuffs and facing charges of espionage. He was shown being bundled out of a blue van by masked Russian security officers and then being locked in a small, barred chamber. Russian television cameras panned across a table said to display his belongings: more than $6,000 in cash, a mobile telephone and what Russia’s Federal Security Service, or F.S.B., described as “intelligence related” devices, including a Taurus pistol and bullets.

The cameras lingered on the gun, showing a close-up of lettering on the barrel — “Made in Miami, Fla., U.S.A.” — and sending what many in the Baltics interpreted as a blunt warning from Moscow that, despite whatever support America has shown former Soviet lands, Russia could still act as it pleased in this part of the world, even in countries that belong to NATO.

Anders Fogh Rasmussen, the departing secretary general of the alliance, said that Estonia had not raised Mr. Kohver’s abduction “in the context of NATO” and that Russia’s intentions were difficult to fathom. “It is hard to guess about motives in the Kremlin but personally I think they are all the way through testing our vigilance,” Mr. Rasmussen said in an interview in Brussels, the alliance’s headquarters.