FACTBOX - U.S. experts see more dangerous world for Americans

(Reuters) - A majority of top U.S. foreign policy experts say the world is a more dangerous place for Americans today than just six months ago, thanks largely to the war in Iraq and a failing U.S. war on terrorism, a new survey shows.

A majority of the 108 experts polled by Foreign Policy magazine and the Center for American Progress also said they would expect another September 11-scale attack within the next decade, despite substantial improvements among U.S. security, law enforcement and intelligence agencies.

The findings appear as a Terrorism Index in the September/October issue of Foreign Policy magazine, which is published by the Carnegie Endowment for International Peace.

The survey was conducted on May 23 to June 26.

Following are the top countries named by experts as posing major challenges to U.S. national security policy.

* Which country is most likely to become the next al Qaeda stronghold?

Pakistan.......35 percent

Iraq...........22 percent

Somalia........11 percent

Sudan...........8 percent

Afghanistan.....7 percent

* Which countries are most likely to transfer nuclear technology to terrorists in the next three to five years?#

Pakistan.......74 percent

North Korea....42 percent

Russia.........38 percent

Iran...........31 percent