America was once the most admired nation on earth. Today she is despised.
According to the Pew Global Attitudes Project, even those nations that once admired America no longer view her favorably. This report was recently cited by David O. Smith at the Center for Contemporary Conflict at the Naval Postgraduate School in Monterey, California, who noted that the Pew survey pegged the favorability rating of the United States in Pakistan at only 27 percent, but Smith noted that
A Western diplomat in Islamabad stated that a methodologically sound public opinion poll commissioned by his embassy recently tabulated the response of 1000 Pakistani citizens and found only a four percent favorability index for the United States.
Pakistan is supposed to be an "ally" of the U.S., receiving substantial foreign aid. Even U.S. "allies" despise the U.S.
The United States federal government is really what is despised, not necessarily the American people. But the American people deserve to be despised if they allow their government to do things that other nations justifiably despise. What does the federal government do to anger other nations? What should it do in order to regain the respect and admiration of the world?
The federal government is responsible for the deaths of nearly two million people in Iraq since 1989. More deaths could be attributed to the U.S. if we include murders by Saddam Hussein, who received foreign aid from the U.S. federal government during his war with Iran.
Iraq
That webpage shows the contrast between the foreign policy of a Christian nation and the foreign policy of a secular empire. See also:
Imperialism
Around the world, the presence of the federal government and the U.S. military is more pronounced than the presence of American businessmen and missionaries. This is the short answer to the question, why is America despised?
Why All the Foreign Bases? by Sam Baker