LONDON—It’s not just suspicious cable cuts, arson attacks, parcel bombs, and the weaponization of migration. All of these forms of aggression have already hit Europe, causing considerable harm and expense, but they’re far from the only attacks below the threshold of war to have hit Europe in recent years. In fact, hostile actors seem to think up new forms of subthreshold aggression almost monthly.
NATO should take on a more active role in coordinating the response to such attacks and in helping allies build response options. Specifically, the Alliance should use the upcoming NATO Summit in Ankara to establish response options for its member states.
People, including some NATO officials, often refer to hostile activities below the threshold of Article 5 as “hybrid warfare.” That term, however, isn’t quite accurate. “Hybrid” denotes a combination of things that are very different: For example, a hybrid car uses both gasoline and electricity. As Frank Hoffman, who coined the term “hybrid war,” explained in 2007, “Instead of separate challengers with fundamentally different approaches (conventional, irregular or terrorist), we can expect to face competitors who will employ all forms of war and tactics, perhaps simultaneously.” Hybrid war is, in other words, the combination of conventional war with irregular forms of aggression. Thus, “subthreshold” or “gray zone” are more accurate descriptions of the types of recent attacks on some NATO member states.
