When you extrapolate
1) the increasingly-vaguely-worded and -legally-authorized reach of national governments to act in what might be defined broadly as "military" ways wherever they see fit
2) plus the ever-increasing capabilities of non-state actors (some call them terrorists, when it's convenient) and the state-sponsors that back them, not to mention the actual inability of states to closely control these assets
3) the (current) ability to execute such actions through proxies/remotely/etc such that they are nearly perfectly anonymous
4) and the increasingly brittle infrastructure of a modern, interconnected, INTEGRATED data- and electronically-driven (mostly Western) society.
The intersection of these lines seems inevitable: a non-state actor (perhaps sponsored by a state, whether or not this specific action IS sponsored/authorized) is going to accomplish something really heinous, like a Chernobyl-level meltdown, or perhaps the destruction of the electrical grid across the East Coast of the US (something that costs $billions and/or thousands+ of lives).
What happens then? If the US is catapulted into a paroxysm of 10 years of war over the relatively puny-but-showy 3000 deaths of the WTC attack, what would we do if that casualty number was 20,000? 100,000?
"Someone will need to pay dearly" would seem to be the logical response of this otherwise-torpid democracy. But what if we don't know who that is, or (almost worse) are only "pretty sure" we know who it is?