Obviously Iraq is the reason for this question coming to mind. The only other example I can think of is Truman withdrawing troops from Korea in 1948. Can you guys think of any others?
There are many nations where the United States temporarily landed troops in a non-combat role to protect its own citizens or their property: Honduras, for example, where U.S. troops landed six times from 1903 to 1925.
Brief punitive expeditions were launched twice in Indonesia in the 1830s and three times in Fiji over the next two decades.
More forceful intervention was called for in unstable nations or those the U.S. government deemed hostile to its interests: Republican China, where U.S. troops operated at will throughout much of the nation, or then-independent Hawaii.
The United States has a long history of occupying and re-occupying Latin American nations - notably Cuba, which was occupied twice (1898-1902 and 1906-1909) before interventions in 1912 and 1917 (and the 1960s). The Dominican Republic, Haiti, and Nicaragua are other examples of long occupation following brief interventions.