WASHINGTON — Secretary of State John Kerry has accused Russia of behaving in a “19th-century fashion” because of its annexation of Crimea.

But Western experts who have followed the success of Russian forces in carrying out President Vladimir V. Putin’s policy in Crimea and eastern Ukraine have come to a different conclusion about Russian military strategy. They see a military disparaged for its decline since the fall of the Soviet Union skillfully employing 21st-century tactics that combine cyberwarfare, an energetic information campaign and the use of highly trained special operation troops to seize the initiative from the West.

“It is a significant shift in how Russian ground forces approach a problem,” said James G. Stavridis, the retired admiral and former NATO commander. “They have played their hand of cards with finesse.”

The abilities the Russian military has displayed are not only important to the high-stakes drama in Ukraine, they also have implications for the security of Moldova, Georgia, Central Asian nations and even the Central Europe nations that are members of NATO.