The U.S. Has Been At War 222 Out of 239 Years. An interesting statistic: America has been at war 93%  of the time – 222 out of 239 years. Another way to put it: the U.S. has only been at peace for less than  20 years total since its birth. (Mar. 19, 2017) To put this in perspective: * No U.S. president truly qualifies as a peacetime president. Instead, all U.S. presidents can technically  be considered “war presidents.” * The U.S. has never gone a decade without war.