It's a reasonable question, but is it practical? 9/11 only killed a fraction of the number who probably died in the last few days in the recent typhoon, but the effect was to bring the entire country and economy to a halt.

The US would need statesmanship beyond that of Churchill to galvanize and harden society against those eventualities.

Moreover, in an era of dirty bombs, chemical weapons and even full nuclear devices, the consequences might not always be merely a "handful of casualties," and the grotesque effects of certain weapons, particularly on children, would be images that would be highly likely to incite increasingly aggressive responses.

The US historically is not a society that is accustomed to the idea of being under any kind of siege, nor of allowing its families to remain under threat of any kind. That's not the underlying narrative, and it's just not in its DNA.