Amurka ta fara karni na 21 a matsayin babbar ƙasa mai iko da babu wanda ya kai ta. A duniya, Amurka ta taɓa kowa ta hanyoyi daban-daban: ta hanyar Hollywood, fasahar Amurka - Microsoft, abincin gaggawa - MacDonald's, abubuwan sha masu kumfa - Coca Cola, kafofin watsa labarai - CNN, kafofin buga labarai - New York Times, International Herald Tribune, intanet - Google, Yahoo, da kuma kuɗi - Wall Street. Fiye da ƙarni ɗaya, Amurkan ta mamaye siyasa, tattalin arziki, manufofin ƙasashen waje da duniyar haɗin kai.

The USA began the 21st century as the world’s unrivalled superpower. Globally the USA touched everyone in different ways, through Hollywood, US technology - Microsoft, fast food - MacDonald’s, fizzy drinks - Coca Cola, news media - CNN, print media - the New York Times, International Herald Tribune, internet - Google, Yahoo, and finance - Wall Street. For over a century the United States of America has dominated politics, economics, foreign policy and globalisation.

Lokacin da George W Bush ya zama shugaban Amurka a shekarar 2001, masu ra'ayin Neoconservatives, waɗanda suka cika gwamnatinsa, sun yi magana game da buƙatar nuna ƙarfin Amurka har zuwa karni na gaba. Sun yi magana game da alƙawuran ƙasa da ƙasa, dokar ƙasa da ƙasa da yarjejeniyoyin duniya a cikin "shirinsu na karni na 21," cewa suna hana ƙarfin Amurka, kuma Amurka ba ta buƙatar su saboda ita ce babbar ƙasar duniya.