Top 10 powerful female world leaders Why is the USA still lagging behind?

The rest of the world, including third world countries have elected women presidents and prime ministers over and over again. The United Kingdom has had reigning women monarch for centuries, and an elected female prime Minister. Canada has had a female prime minister even though short lived. India, Sri Lanka, Germany and others have long history of women heads of government. When will the USA joining the 21^st century. Below is a list of only 10 more than 20 female world leaders within the last 5 years.

   1) Denmark: Prime Minister Helle Thorning-Schmidt

S   2) Slovenia : Prime Minister Alenka Bratusek

     3) Germany: Chancellor Angela Merkel

    4) Argentina: President Cristina Fernandez de Kirchner

     5) Liberia: President Ellen Johnson-Sirleaf

    6) South Korea: President Park Geun-hye

    7) Brazil: President Dilma Rousseff

    8) Switzerland: President Simonetta Sommaruga

    9) Chile: President Michelle Bachelet

     10) Norway: Prime Minister Erna Solberg