Les plans ne valent rien, mais planifier vaut tout.
Prononcé dans un discours en 1957
tsk
Contexte et précisions
En anglais : "I tell this story to illustrate the truth of the statement I heard long ago in the Army: Plans are worthless, but planning is everything. There is a very great distinction because when you are planning for an emergency you must start with this one thing: the very definition of "emergency" is that it is unexpected, therefore it is not going to happen the way you are planning." (From a speech to the National Defense Executive Reserve Conference in Washington, D.C. (November 14, 1957) )
En anglais , la reformulation suivante est fréquente :
"Plans are nothing; planning is everything."