A man armed only with a knife may decide that a bear prowling the forest is a tolerable danger, inasmuch as the alternative – hunting the bear armed only with a knife – is actually riskier than lying low and hoping the bear never attacks. The same man armed with a rifle, however, will likely make a different calculation of what constitutes a tolerable risk. Why should he risk being mauled to death if he doesn’t have to?

Robert Kagan