Many media in the world pointed out that the important root of terrorism is the Middle East policy of the United States. The long-term military conflict between Israel and Palestine, the killing of Palestinians by Israelis and the partiality of the United States towards Israel have all "created" fanatical radicals who are determined to die. Both the BBC and Le Monde pointed out that "the crux of the problem lies in the US Middle East policy." The British "Guardian" pointed out that "justice is the best defense" and that Americans must be "fair" in order to truly stop Osama's widespread support in Arab and Muslim societies.

Some people think that the attack is a political conspiracy. The main doubts include the possibility of the plane hitting a skyscraper, the gap diameter of the Pentagon does not match the diameter of the plane, the debris of United Airlines Flight 93 and the life and death of the hijacker. Conspiracy theorists believe that the purpose of the attack is the Bush administration's self-directing, self-acting, safeguarding the international status of the United States, achieving hegemony and peace, and controlling the world.

The "9 1 1" incident was the most serious terrorist attack in the United States, with a total of 2,996 victims. There are different statistics about the property losses in this incident. According to a report released by the United Nations, the economic losses caused by this terrorist attack amounted to 200 billion US dollars, equivalent to 2% of the GDP of that year. The loss caused by this incident to the global economy even reached about 1 trillion dollars.