Theodore Roosevelt actually said...
It is not merely a great thing, but an indispensable thing that the nation' s citizens should be ready and willing to die for it in time of need; and the presence of no other quality could atone for the lack of such readiness to lay down life if the nation calls.
Context
Remarks on the Occasion of the Unveiling of the Soldiers' and Sailors' Monument at Arlington, Under the Auspices...
05/20/1902