I have long been concerned that cyber warfare planners are exaggerating the value of offensive operations and under-resourcing efforts to build cyber defenses. P.W. Singer and Allan Friedman have an article in FP that elaborates this point and warns that it's as misleading as the pre-1914 "cult of the offensive" that helped trigger world war I.
The authors say offensive cyber R&D is 2.5 to 4 times as much as R&D on cyber defense. They also note the military cultural bias in favor of offense over defense, despite the strong evidence that this is not the case in cyber war. I hope their message is heeded.