I have noticed two things related to this:

1. The term `irony` is often used to refer to heavily-veiled passive aggression.

1a. I think Millon provides a great description of the sort of behavior we all have encountered, although no longer (as of DSM-IV) considered a personality disorder: "They cannot decide whether to adhere to the desires of others [...] or to to turn to themselves [...], whether to be obediently dependent on others or defiantly resistant and independent of them, whether to take the initiative in mastering their world or to sit idly by, passively awaiting the leadership of others; they vacillate, then, like the proverbial donkey, moving first one way and then the other, never quite settling on which bale of hay is best. [...] ...only one essential trait is specified in characterizing the passive-aggressive personality type, that of resistance to external demands" (Millon 1981, Disorders of Personality, 244-245).

1b. I think (1a) is part of the reason why you might say that "Americans don't get irony... [a]t all". You might be confusing their lack of appreciation for irony with their recognition of and consequent disregard for passive aggression. Also, irony is highly culturally dependent.

2. My preferred method of dealing with the chronically overconfident is to ask kind and honest questions. I do not use irony; I do not use passive aggression; I do not throw punches. Instead, I assume that these people are telling the truth or overcompensating b/c of some hidden anxiety. In the first case, I think they're wrong; in the second, I think they're in need of growth. For either, I've found that the best response is to be gentle and to learn about their presuppositions.

Let's review the distinction between terrorist and enemy combatant (although some of us may have lost sight of it):

Terrorist: member of a small group of persons who wish to cause outsize havoc in the dim hope of changing larger groups of persons

Enemy combatant: member of a large group of persons who can and do cause havoc in a rather reasonable hope of changing similarly sized groups of persons

Now, if it's not obvious already, let's realize that large groups necessarily start off small.

In fact, corporal punishment is permitted in many parts of the US: "The Supreme Court has since, in the 1977 Ingraham v. Wright, upheld the right of public schools to use corporal punishment (in some ways the same punishment Bishop said may not be used in prison), and twenty-two states still permit corporal punishment in school" (Moskos, In Defense of Flogging, 2011: 109-110). Negative reinforcement is not generally an effective means of promoting knowledge, however.