A lot of NATO countries already publicly consider being under "hybrid" attacks: disinformation, sabotage, espionnage, &c. There isn't much more you can do with

A lot of NATO countries already publicly consider being under "hybrid" attacks: disinformation, sabotage, espionnage, &c. There isn't much more you can do without going into an armed conflict, so what would be needed to happen is the will to sacrifice a large amount of their citizen and/or expose themselves to possible strikes