to try to provide against having to do either

Revolution thus ran its course from city to city, and the places which it arrived at last, from having heard what had been done before, carried to a still greater excess the refinement of their inventions, as manifested in the cunning of their enterprises and the atrocity of their reprisals. Words had to change their ordinary meaning and to take that which was now given them. Reckless audacity came to be considered the courage of a loyal ally; prudent hesitation, specious cowardice; moderation was held to be a cloak for unmanliness; ability to see all sides of a question, inaptness to act on any. Frantic violence became the attribute of manliness; cautious plotting, a justifiable means of self-defense. The advocate of extreme measures was always trustworthy; his opponent a man to be suspected. To succeed in a plot was to have a shrewd head, to divine a plot a still shrewder; but to try to provide against having to do either was to break up your party and to be afraid of your adversaries. 

The Peloponnesian Wars | Thucydides