An audiotape released Tuesday and attributed to Al Qaeda's No. 2, Ayman Zawahiri, castigated Egyptian officials for turning their country into an "international station of torture in America's war on Islam."
Why Obama chose Egypt
Egypt was a logical choice for the speech, most observers say. With 80 million people, it is the most populous Arab state and an important player in Islamic and Arab affairs, though its influence has waned in recent years due to internal economic and political problems.
"This is a very important and historical moment for the United States to build a serious and organic bridge between Arab and Islamic culture and American culture," says Nabil Abdel Fattah, assistant director of the Cairo-based Ahram Center, a think tank with ties to the government.
"We are one of the two or three oldest peoples and nations in the world," he says. "Obama was correct to choose Egypt as the location to address the entire Islamic world."
The president has seeded the ground for his Cairo speech with conciliatory remarks toward Muslims, first in his Inauguration Day address when he urged relations built on "mutual interest and mutual respect" and then in a January interview with the Saudi-owned television channel Al Arabiya. Speaking in the Turkish parliament in early April, Obama stressed that the US "is not and never will be at war with Islam."