> Obama telling Putin to "cut it out" isn't enough
As far as I know, that isn't the plan, and retaliation is planned. Do you know otherwise?
People instinctively want a strong, immediate response in kind. From what I understand, that's actually the wrong way to respond. Here are a couple of points to consider, based on reading a lot of experts (I'm not one myself):
* 'The task of international relations is to prevent C level problems from becoming A level problems.' (I forget where I read that.) Escalation rarely is desirable. That doesn't mean that you don't respond, but that you need to respond in a way that doesn't escalate and put your adversary in a political position where they must re-escalate (e.g., because their populations are angry and demand it). That's how wars begin, often despite the intentions of leaders. Threading that needle is difficult, but that's what the situation demands. For example, after some bad behavior by North Korea, the U.S. responded by flying one or two nuclear capable bombers in an exercise over S. Korea; the point was made but not in a way that required re-escalation by the North.
* "the threat of asymmetric punishment - striking wherever, whenever, and with flexible means rather than retaliation-in-kind in a theater of operations chosen by an adversary - can be an effective instrument of deterrence". [0] If you respond immediately and in the same way your opponent attacked you, you are letting them manipulate you and the situation: They decide when, where, and how you act and the battle takes place (assuredly they will chose situations to their advantage).
Based on the above, a good response has to be smartly chosen to effectively send a message but not invite escalation, and should be at a time, place, and manner of your choosing.
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[0] Toward a New Offset Strategy: Exploiting U.S. Long-term Advantages To Restore U.S. Global Power Projection Capability by Robert Martinage, Center for Strategic and Budgetary Assessments [a leading defense think tank]
http://csbaonline.org/research/publications/toward-a-new-off...