[tetha]

It might be a reference to the blue-team red-team asymmetry, and how in cybersecurity the attacker has an advantage. The attacker there only needs one success and can rapidly try different avenues, while the blue team just needs to miss patching one system and that's it. And while patching may be technically simple, the organizational efforts around it are sometimes... eh.

In war, defenders can entrench more and more and a lot of work and planning is put into hitting either before the defenses are up, or not at all.