A military attack against Iran remains an option should the Middle East nation continue to pursue its nuclear ambitions, Defense Secretary Robert Gates suggested Tuesday. "This is not about changing the regime in Iran," Gates told a group of community leaders at a Whiteman Air Force Base lunch. "It's about getting the regime in Iran to change its behavior, and its policies." Talk of a possible US attack on Iran has surfaced frequently this year, prompted in some cases by hard-line statements by White House officials. President George W. Bush has said that Iran's continued pursuit of nuclear arms could lead to World War III. While Gates has previously emphasized diplomacy and the use of economic sanctions, he told an audience member at the officers' club lunch, "We have to keep all of our options open." At the same time, Gates added, "My own view is that another war is the last thing the Middle East needs right now." The brief appearance marked a homecoming for Gates, a native of Wichita, Kansas, who began his military career as a second lieutenant at the base 75 miles east of Kansas City. Gates later served as director of the CIA under the first President George H.W. Bush. He was appointed secretary of defense in November 2006, succeeding Donald Rumsfeld. Gates' speech was primarily a recollection of the two years he spent at Whiteman Air Force Base in the late 1960s before embarking on a 26-year career with the CIA. He did not take questions from reporters but responded to four questions from members of the base community council. The council is a support group consisting of elected officials and civic leaders from 17 surrounding cities and towns. One audience member asked Gates about potential conflicts with China, which the defense secretary visited earlier this month. He assured the council members that despite China's "lack of transparency" over its military expansion, growing defense budget and an anti-satellite test conducted in January, the communist nation is an important US ally. "We have huge mutual interests, above all economic," said Gates, who met with Chinese President Hu Jintao and other top leaders on his recent Asia visit. He also traveled to South Korea and Japan. Gates also addressed the continuing war in Iraq, noting that despite continued difficulties in Baghdad, the war effort in Iraq has seen "significant improvement" in the outlying provinces.