Definition of vicissitude:
regular change or succession from one thing to another, or one part of a cycle to the next; alternation; mutual succession; interchange; (often plural) a change, especially in one's life or fortunes
"the vicissitudes of war in Iraq cast a dreary backdrop for Donald Rumsfeld's first visit to Asian military allies since he became US Defense Secretary in 2001. "US redeployments afoot in Asia." Christian Science Monitor. 2003 Nov. 18. Pg. 6."