Editor's note: This article is being updated throughout the day.
Egyptian President Hosni Mubarak relinquished power on Friday, just a day after he steadfastly refused to step down. To catch you up on the ever-changing situation in Cairo, the Explainer offers the following roundup of questions from our readers. (Latest update: 4:15 p.m. ET.)
What role did the White House play in Mubarak's resignation?
We don't know yet. President Obama was in a meeting when he learned that Mubarak had resigned, and a spokesman said the two men had not spoken before the public announcement. However, there is some indication that indirect U.S. pressure played a role. Defense Secretary Robert Gates spoke with Field Marshal Mohamed Hussein Tantawi, who heads the Supreme Council of the Armed Forces, just hours before Suleiman announced Mubarak's resignation, and it was the military that likely forced Mubarak's hand.
OK, so which Middle Eastern government is going down next?
Maybe Algeria. Andrew Lebovich of the New America Foundation points out that Algeria, like Egypt, faces high unemployment, large-scale corruption, and a long-serving president. Abdelaziz Bouteflika, while a rookie compared to Mubarak, has held office for 12 years. The country has been in a state of emergency since 1992 and was the site of massive protests in January. But Algeria doesn't have anything like a united opposition movement, and the president's political rivals seem to dislike each other at least as much as they dislike him.
Others point to the Iranian regime as the next victim. Barbara Slavin notes that Mubarak resigned on Iran's Islamic Revolution Victory Day and suspects that Ayatollah Ali Khamenei fears the revolutionary spirit could rise in Iran once again. The Iranian government has arrested several opposition figures as a precautionary measure.
There are still more candidates. Jordan has a hereditary monarchy and complex demographics. Saudi Arabia is a possibility, too. King Abdullah was so concerned about the toppling of Mubarak that he considered replacing the potential loss of U.S. aid if the Egyptian president stayed on.
Who's in charge of Egypt right now?
The Supreme Council of the Armed Forces. Vice President Omar Suleiman addressed the nation Friday, noting that President Mubarak had resigned and handed over authority to the council, which includes the chief of military intelligence, the heads of each branch of service, the chief of the General Staff, and most of the military's other top officers. The council was formed by former President Gamel Abdel Nasser with the passage of Law Number Four in the aftermath of Egypt's crushing defeat in the Six-Day War of 1967.
What does the Egyptian Constitution have to say about all this?
Not much. If Mubarak had maintained his title of president, his decision on Thursday to assign all powers to Vice President Omar Suleiman would have been consistent with Article 82 of the Constitution. Now that he has resigned, the nation seems to have abandoned any semblance of constitutional order.
Egypt's Constitution was first adopted in 1971. Article 84 of the document states: "In case of the vacancy of the Presidential Office or the permanent disability of the President of the Republic, the President of the People's Assembly shall temporarily assume the Presidency."
Ahmad Fathi Sorour has been the head of the People's Assembly since 1991 and would be in line to assume the presidency. However, like most of the politicians from the National Democratic Party, he has mostly served as a Mubarak puppet, and neither Mubarak nor the military favor him to lead the country through crisis.
What about Vice President Suleiman—wasn't he put in power just yesterday?
He may be out of the picture. Even if the country's Constitution were in effect, it wouldn't say what happens to the vice president when his boss resigns. There's no precedent for this sort of thing, since Suleiman was appointed less than a month ago and is the first person to have that job under Mubarak. But an Egyptian legal analyst who spoke with the BBC argued that when the president leaves office, the vice president goes with him.
Is the Muslim Brotherhood about to take over?
It's hard to say. Mubarak would never allow a pollster to gauge the brotherhood's support among ordinary Egyptians. The group won only 20 percent of the parliamentary seats in the 2005 elections, but that's a poor barometer of their popularity, since the turnout was below 25 percent and President Mubarak took several legislative measures (PDF) to make it difficult for members of the group to get on the ballot. If the military holds elections this year and allows representatives from the brotherhood on the ballot, there's no way of knowing how they'd do at the polls.
Even if the brotherhood did manage to gain power, it's debatable how catastrophic that would be for the relationship between Egypt and the West. The group has softened its Islamist tone in recent years, and has even agreed to abide by the Camp David Accords. (Read Shadi Hamid's take on the Muslim Brotherhood , and a FAQ on the Brotherhood's political priorities from the Council on Foreign Relations.)