VILNIUS, Lithuania — Dozens of United States Special Operations forces are now in the Baltics to bolster the training and resolve of troops who are confronting a looming threat from Russia, and to enhance the Americans’ ability to detect Moscow’s shadowy efforts to destabilize the former Soviet republics.

“They’re scared to death of Russia,” Gen. Raymond T. Thomas, the head of the Pentagon’s Special Operations Command, who visited here recently, said of the tiny militaries of Latvia, Lithuania and Estonia. “They are very open about that. They’re desperate for our leadership.”

As a result, General Thomas said, American commandos now have a “persistent” presence here with Baltic special operations troops, after forging close ties with them over the past decade while fighting together in Iraq and Afghanistan. The Americans bring sophisticated surveillance technology and broad sources of intelligence. The Baltic partners have a deep understanding of conventional Russian military might as well as Moscow’s increasing use of cyberwarfare, information subterfuge and other means less than all-out war to weaken the Western-backed governments.

It is unclear how supportive President-elect Donald J. Trump will be of this initiative as he aims to mend fences with Moscow. Mr. Trump suggested during the election campaign that only NATO allies that paid their fair share deserved protection from the United States, although he has since softened his warning. His remarks alarmed the Baltic nations, which count on NATO’s collective security efforts to deter an unpredictable Russia.