peace dividend

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An amount of money taken from a defense budget and appropriated elsewhere in times of peace when less money is required for defense than in times of hostility or war.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun an economic benefit gained from a reduction in defence spending, especially a fund of public money that would be available for other purposes