If our opponents are really to believe that we shall sacrifice American lives and risk terrible destruction to oppose their aggression, we must, for all practical purposes, be in fact willing to do so. We cannot say we are firm and be cowardly, for our words will be a 'specious appearance.' In managing a detterance policy, there is no substitute for courage. A nation cannot follow a more dangerous and wasteful course than to be projecting a worldwide threat - as we are unavoidably doing today - and yet manifest a lack of courage to sustain it.
As an example. Minister of Foreign Affairs Otto von Bismarck relates the following episode:
It is well known that the French ambassador entered my office as late as August 6, 1866, with the briefly worded ultimatum: 'Either cede to France the city of Mayence, or expect an immediate declaration of war.' I was, of course, not one moment in doubt about my reply, I said to him 'Well, then, it is war.'
It ends on a happy note for Germany as Bismarck recounts:
He proceeded with this reply to Paris. There they changed their mind after a few days, and I was given to understand that this instruction had been wrung from Emperor Napolean during an attack of illness.
Source: The American Threat: The Fear of War as an Instrument of Foreign Policy. James L. Payne. Markham Publishing Company, Chicago. pg 154-155.