Western countries are facing an “unprecedented volume” of possibly deadly attacks believed to be perpetrated by Russia that do not meet the threshold for armed conflict, and governments are rapidly trying to increase their readiness in the face of these threats, according to experts testifying to Congress.

European countries have accused Russia of repeatedly carrying out “hybrid” or “gray zone” attacks, which can include jamming communication systems, cyberattacks, sabotage such as arson and the cutting of undersea cables, and more. And these attacks appear to be becoming more frequent.