There have been two big surprises in Russia’s invasion of Ukraine.

The first is obvious: the horrific performance of the Russian forces. The second is less obvious — in fact, it’s almost invisible: the seeming absence of a cyberwar. Russia was supposed to first launch an all-out cyberattack that would paralyze Ukraine and prepare the ground for the physical assault that followed.

Instead, in many tellings, cyberwar was “the dog that didn’t bark.” That is an exaggeration. Russia did engage in cyber activity, but the impact has been much different from that which was anticipated. There are important lessons to be learned from the cyberwar against Ukraine, and they challenge basic assumptions about 21st-century conflict.