1983年罗伯特·卡根为[[纽约州]]共和党[[众议员]][[杰克·肯普]]担任外交政策顾问。1984至1986年，在美国总统[[罗纳德·里根]]任内，他担任美国国务卿[[乔治·普拉特·舒尔茨]]的演讲稿撰写人并作为[[美国国务院]]政策计划研究员之一。1986至1988年，他在美国国务院美洲事务局任职 。<ref name="Three-Part Lecture Series at the Kluge Center Looks at Foreign Policy Through the Lens of Realpolitik">{{cite web | url=http://www.loc.gov/today/pr/2014/14-030.html?loclr=rssloc | title=Three-Part Lecture Series at the Kluge Center Looks at Foreign Policy Through the Lens of Realpolitik | publisher=Library of Congress | date=21 February 2014 | accessdate=21 February 2014 | author=Steinhauer, Jason}}</ref>1997 。1997 年，卡根与{{link-en|威廉·克里斯托尔|William Kristol}}联合创立了{{link-en|新美国世纪计划|Project for the New American Century}}<ref name=neoconreader/><ref name=pnac/> 。自1998年至2010年8月，卡根担任[[卡内基国际和平基金会]]高级研究员。2010年9月他被任命为[[布鲁金斯学会]]美国中部和欧洲高级研究专员。<ref>[http://www.brookings.edu/media/NewsReleases/2010/0908_kagan.aspx Robert Kagan joins Brookings] {{webarchive|url=https://web.archive.org/web/20121011095052/http://www.brookings.edu/media/NewsReleases/2010/0908_kagan.aspx |date=2012-10-11 }}{{Primary source-inline|reason=|date=2015年1月}}</ref><ref>[http://www.carnegieendowment.org/experts/index.cfm?fa=expert_view&expert_id=16 Profile on the Carnegie Endowment for International Peace site] {{webarchive|url=https://web.archive.org/web/20050514080156/http://www.carnegieendowment.org/experts/index.cfm?fa=expert_view&expert_id=16 |date=2005-05-14 }}{{Primary source-inline|reason=|date=2015年1月}}</ref><ref>Robert Kagan, "I Am Not a Straussian", ''Weekly Standard'' 11: 20 (February 6, 2006)</ref><ref>[http://www.yaledailynews.com/article.asp?AID=30540 "Robert Kagan Follows Father but Forges Own Path"] {{webarchive|url=https://web.archive.org/web/20060319033109/http://www.yaledailynews.com/article.asp?AID=30540 |date=2006-03-19 }}, Andrew Mangino, Yale Daily News</ref>