The use of force is easy to rationalize in terms of basic economics. 'We should make them PAY for what they've done!' It's just the law of demand: raise the price of crossing us, and fewer people will cross us. Make the price another Hiroshima, and perhaps the quantity demanded will fall to zero.
In a modern democracy, not only can a libertarian be elitist; a libertarian has to be elitist. To be a libertarian in a modern democracy is to say that nearly 300 million Americans are wrong, and a handful of nay-sayers are right.