MOSCOW — The casual reader of The New York Times may be forgiven for thinking he or she had dozed off and awakened in a John le Carré novel. How else to explain the sudden increase of bombers in the skies over Europe, kidnapped spies, troop buildups in Eastern Europe and roaming submarines in the Baltic Sea?

Much of what we see today, we hope, is bluster, as when a popular Russian television host reminded his prime-time audience that Russia could reduce the United States to “radioactive dust” (to help explain why President Obama’s hair was graying).

But something has indeed been afoot since Vladimir V. Putin resumed the presidency of Russia in 2012 and sought to push back against the West, which he has accused of meddling in Russia’s backyard.

Here are recent examples of Russia’s new assertiveness. Of course, none of this has been confirmed by Moscow.