Fortitude by Philip Inman

Philip Inman one day saw a card bearing the words "This too will pass" upon the desk of the Russian Ambassador, M. Maisky. He asked about it and received the explanation.
"I have had so many varied experiences. Sometimes the crowds have gathered outside the Embassy, booing and jeering – so angry that they would not have stopped at physical violence. Then I have looked at the words on the card and I knew it would pass. At other times the crowds have assembled cheering – when my country came into the war, for instance. Feeling perhaps a little too elated, that card would bring me back down to earth again. That too would pass.