Let me explain (I am not a deterrence theorist, but I play one on TV):
The basics of deterrence are: if you do x, I will harm you and harm you in ways that are greater than the benefits of you doing x AND (here what is often ignored) I will harm you in ways that are worse than either the current status quo or where you think the status quo is shifting. The US, for instance, sanctioned Japan in response to its aggression (cutting off oil sales, if I remember correctly) so that the situation was worsening for Japan. This undercut deterrence because the "doing x" seemed to be more attractive, not less, compared to the shifting status quo.
Much of the focus of deterrence is on the credibility of the threat--will you do the costly thing to create harm for the target (which often creates harm for the deterring country)--but there is the other side of the question--what I call the Big Brother problem.*
For deterrence to work, one has to threaten harm if the target does something you don't want AND one has to assure the target that they will not be harmed if they do something you want. You have to be able credibly to accept yes as an answer. Can this administration do that, especially from the Iranian standpoint? Iran agreed to the nuclear deal which limited its nuclear aspirations (we can argue all day about whether it was good enough, whether it complied fully), and then the Trump Administration said it was not good enough and dropped out of it, threatening maximum pressure.
For the Iranians, it seems like the US could not take "yes, we agree" as an answer. For the Trumpers, they can say that they cared more about other behavior, and, yes, other behavior--supporting Hezbollah, doing all other kinds of awful stuff--was problematic. But in a bargaining situation, when you say, nope, we are not going to take yes for an answer, it changes the dynamic quite a bit. And, yes, to engage in bargaining, you have to think not just about what you are thinking but what the other side is thinking and preferring. The whole idea of "strategic" is about getting inside the head of the other
Coming back to the shorthand, to use violence is an admission that deterrence is not working. It is still coercive diplomacy, but a harder, less successful form: compellence. Compellence is mostly about using force to get others to change their behavior (see these handy lecture notes from Branislav L. Slantchev). The Kosovo bombing campaign is a successful example, and there is a lot of regret about that one. That is much harder for all kinds of reasons:
- It tends to require the other side to make a visible change in policy, losing face, whereas deterrence simply requires the other side to keep not doing something.
- It is not just about losing face--the other side had a reason to be doing what they were doing, so altering their preference structure or changing the costs they face is harder than maintaining the status quo.
- I forget the rest....
So, yes, I am reminded of 2003 in that these are the wrong people seemingly planning the wrong war at the wrong time (the time thing is about how all of this undercutting the ISIS fight). Any pleasant callbacks or analogies that I am forgetting?
* No, my big brother didn't abuse me. Just thinking about a well known kind of dynamic.