The Truman Doctrine of containment was a United States policy to stop Soviet expansion during the Cold War. United States President Harry S. Truman pledged to contain communism in Europe and elsewhere and impelled the US to support any nation with both military and economic aid if its stability was threatened by communism or the Soviet Union. The Truman Doctrine became the foundation of the president's foreign policy and placed the U.S. in the role of global policeman. As Foner reminds us, the Truman Doctrine "set a precedent for American assistance to anticommunist regimes throughout the world, no matter how undemocratic, and for the creation of a set of global military alliances directed against the Soviet Union".

　　1.杜鲁门主义

　　杜鲁门主义是在美国总统杜鲁门任期内形成的美国对外政策，成为第二次世界大战后美国的对外政策核心。1947年3月12日杜鲁门发表国情咨文时，要求国会为援助土耳其和希腊政府，防止当地发生革命，拨款4亿美元。一般认为，这是杜鲁门主义正式形成的起点。杜鲁门主义认为，在世界上任何地区发生社会主义革命，都会威胁到美国的安全。美国要担当“世界警察”的责任，防止共产主义在世界任何地方出现。因此美国实行“马歇尔计划”，援助西欧国家，解救他们战后的贫困，以防止发生革命。大力发展军备，美国仅在1948年一年内就将核武器的储备从13枚扩展到50多枚。因此杜鲁门主义也是冷战的开始，彻底改变了罗斯福时代的美国对外政策，奠定了战后世界的基本格局。杜鲁门主义的出现标示美国对苏联“大国合作，和平缓进”政策归于终结。

　　2.Jimmy Carter

　　James Earl "Jimmy" Carter, Jr. (born October 1, 1924) is an American politician and member of the Democratic Party who served as the 39th President of the United States from 1977 to 1981. He was awarded the 2002 Nobel Peace Prize. Carter, raised in rural Georgia, was a peanut farmer who served two terms as a Georgia State Senator and one as the Governor of Georgia, from 1971 to 1975. He was elected President in 1976, defeating incumbent president Gerald Ford in a relatively close election, running as an outsider who promised truth in government in the wake of the Watergate scandal. He is the second oldest (after George H. W. Bush) of America's four living former presidents.

　　2.吉米·卡特

　　詹姆斯·厄尔·卡特(又称吉米·卡特，1924年10月1日-)，是美国的第39任总统。他早年一直在军队中生活，曾任佐治亚州州长。1976年代表民主党当选总统，在任期间推行能源保护政策。外交方面，卡特积极调停以色列和埃及之间的战争，美国和共产主义国家的关系得到了很好的改善，并和中华人民共和国正式建立外交关系。

　　3.Ronald Reagan

　　Ronald Wilson Reagan (February 6, 1911 – June 5, 2004) was an American actor and politician. He was the 40th President of the United States (1981–89), and served as the 33rd Governor of California (1967–75) prior to his presidency. As president, Reagan implemented sweeping new political and economic initiatives. His supply-side economic policies, dubbed "Reaganomics", advocated reducing tax rates to spur economic growth, controlling the money supply to reduce inflation, deregulation of the economy, and reducing government spending. In his first term he survived an assassination attempt, took a hard line against labor unions, escalated the War on Drugs, and ordered an invasion of Grenada to reverse a Communist coup.

　　3.罗纳德·里根

　　罗纳德·威尔逊·里根(1911年2月6日-2004年6月5日)，美国政治家，第33任加利福尼亚州州长(1967年-1975年)，第40任美国总统(1981年-1989年)。踏入政坛前，里根也曾担任过运动广播员、救生员、报社专栏作家、电影演员，他的演说风格高明而极具说服力，被媒体誉为“伟大的沟通者”，美国人心目中最伟大的总统之一。里根在1980年的选战中击败了当时民主党的总统吉米·卡特，共和党也在同年选举赢得了26年来首次在参议院过半数的席次。里根推行的经济政策为供应面经济学，被人称为里根经济学，将所得税降低了25%、减少通货膨胀、降低利率、扩大军费开支、增加政府赤字和国债，排除税赋规则的漏洞，继续对商业行为撤销管制，使美国经济在历经1981-1982年的急遽衰退后，于1982年开始了非常茁壮的经济成长。他始终强调他对于联邦政府在处理问题上的能力抱持着怀疑态度，尤其是在经济问题方面。他的解决方式是撤回政府的干涉并减少税率和商业管制，以此让利伯维尔场机制能自动修正所面临的问题。