- Bolivia Nationalizes Natural Gas Industry (May 1): Under orders of President Evo Morales, the military takes over the country's energy fields.
- Moussaoui Sentenced to Life in Prison (May 3): A federal jury in Virginia sentences Zacarias Moussaoui to life in prison without the chance of parole for his role in the Sept. 11, 2001, terrorist attacks.
- Israeli Parliament Approves Governing Coalition (May 4): Israeli prime minister Ehud Olmert will control 67 of 120 seats in parliament. Coalition includes his Kadima party, the Labor Party, Shas, and the Pensioners Party.
- Leaders Sign Peace Pact for Darfur (May 5): The Sudanese government and the leader of Darfur's main rebel group agree to a cease-fire that calls on the rebels and the government militias to disarm, will allow 5,000 rebels to join the Sudanese Army, and establishes a fund for the war's victims. Two smaller rebel groups do not join the accord.
- Iranian President Lists Grievances in a Letter to Bush (May 9): In his 18-page letter, Mahmoud Ahmadinejad says that the war in Iraq and the abuse of prisoners by U.S. soldiers contradict Bush's Christian values.
- U.S. Endorses Plan on Palestinian Aid (May 9): European proposal would help Palestinians pay salaries of civil servants and alleviate shortages of food and medicine. Aid has been cut off since Hamas took control of the government.
- U.S. to Renew Ties to Libya (May 15): Bush administration announces plans to normalize relations with Libya, citing Libya's decision to renounce terrorism and give up its nuclear weapons program.
- Hussein Charged with Crimes Against Humanity (May 15): Panel of judges indicts former Iraqi president Hussein on charges of crimes against humanity. Ruling is part of his trial that focuses on the execution of about 150 Shiites in Dujail in 1982.
- U.S. Curbs Sales to Venezuela (May 15): The Bush administration announces it will no longer sell military equipment to Venezuela because the country has refused to cooperate with terrorism investigations.
- UN Panel Recommends Closing Guantánamo Prison (May 19): The United Nations Committee Against Torture denounces the treatment of terror suspects and criticizes the CIA for holding prisoners in secret detention centers overseas.
- Iraqi Parliament Approves Government (May 20): Prime Minister Nuri al-Maliki's cabinet includes 17 members from his Shiite coalition, seven Kurds, seven from a Sunni coalition, and five from a secular alliance. Three important posts—the ministers of defense, interior, and national security—are left vacant.
- Montenegrins Vote for Independence (May 21): Preliminary results from the election commission indicate that 55.4% of voters choose independence from Serbia.
- Bush Meets with Israeli Prime Minister (May 23): President Bush indicates that he supports Ehud Olmert's plan to unilaterally withdraw about 70,000 settlers from the West Bank, but he also encourages Olmert to negotiate with Palestinian president Mahmoud Abbas.
- Bush and Blair Admit Mistakes on Iraq (May 25): In a joint news conference at the White House, president and British prime minister express regret for the abuse of prisoners at the Abu Ghraib prison, for removing all Baathists from positions of power in Iraq, and for other missteps.
- Abbas Challenges Palestinian Government to Accept Peace Plan (May 25): Mahmoud Abbas, president of the Palestinian Authority, says he will call for a referendum on a proposed Palestinian state if the Hamas-led government fails to accept the plan within 10 days.
- Journalists Killed in Iraq (May 29): Paul Douglas and James Brolan, two Britons working for CBS News, are killed by a roadside bomb in Baghdad. A third journalist, Kimberly Dozier, an American, is critically injured.
- Accident Sets Off Riots in Afghanistan (May 29): A truck in a U.S. military convoy crashes into 12 vehicles, killing five civilians. About 15 people are killed and dozens are wounded in anti-American riots that follow the accident.
- U.S. Says It Will Join Europe in Talks with Iran (May 31): Iran, however, must halt its uranium enrichment and reprocessing before the U.S. will enter negotiations.
- Immigrants March in Dozens of U.S. Cities (May 1): More than 1 million people who support the easing the country's immigration laws hold peaceful protests in Los Angeles, Chicago, New York, and other cities.
- House Passes Lobbying Bill (May 3): Votes, 217–213, for reform legislation that attempts to limit earmarks and would require lobbyists to be forthcoming with their activities, stiffen penalties for violations, and require lawmakers and aides to take ethics-training classes.
- CIA Director Resigns Abruptly (May 5): Porter Goss, a former Congressman and CIA officer, steps down after a tumultuous 19 months in the position. (May 8): President Bush selects Michael Hayden, a U.S. Air Force general, as Goss's successor. (May 26): Senate votes, 78–15, to confirm Hayden as the director of the Central Intelligence Agency.
- House and Senate Pass Tax Bill (May 10): House votes, 244–185, to cut taxes on stock dividends and capital gains and extend for one year changes to the alternative minimum tax that will benefit about 15 million wealthy families. Tax cuts total about $70 billion. (May 11): Senate, voting 54–44, passes similar legislation. (May 17): President Bush signs the bill.
- Paper Reports That Government Has Amassed Vast Phone Record Database (May 11): USA Today reports that AT&T, Verizon, and BellSouth have given the National Security Agency telephone records of tens of millions of customers. Both BellSouth and Verizon deny turning over the telephone records.
- Bush Discusses Immigration in Speech (May 15): In a nationally televised address, president presents a plan to station 6,000 National Guard troops at the U.S. border with Mexico. Proposal also offers immigrants a legal route toward citizenship.
- House Votes to End Incentives to Oil Companies (May 18): Votes, 252–165, in favor of renegotiating contracts with oil and gas producers that allow them to avoid paying about $7 billion annually in royalties to the government when they drill in public waters.
- FBI Searches Lawmaker's Office (May 20): In an unprecedented raid, the FBI removes documents from Rep. William Jefferson's Congressional office. Jefferson is accused of receiving hundreds of thousands of dollars in bribes from a small high-tech company, iGate Inc., in exchange for helping it secure contracts with the Nigerian government and companies in West Africa.
- Nagin Reelected in New Orleans (May 21): Incumbent mayor Ray Nagin wins runoff election, defeating Lt. Gov. Mitch Landrieu, 52.3% to 47.7%.
- Electronic Data on Millions of Veterans Stolen (May 22): The Department of Veterans Affairs announces that a computer containing personal information, including the Social Security numbers and birth dates of about 26.5 million veterans, was stolen. An employee brought the computer home, and the computer was stolen during a burglary.
- Senate Passes Immigration Bill (May 25): Votes, 62–36, for legislation that would allow about 11 million illegal immigrants to eventually become citizens, creates a guest-worker program, and enhances security at the border with Mexico.
- Senate Confirms Officials (May 26): R. David Paulison is approved as director of the Federal Emergency Management Agency, and Idaho governor Dirk Kempthorne is confirmed as Secretary of the Interior, succeeding Gale Norton.
- Treasury Secretary Resigns (May 30): President Bush nominates Henry Paulson Jr. to replace John Snow as Secretary of the Treasury.
- Homeland Security Grants Criticized (May 31): Antiterrorism funding is cut by about 40% for New York City and Washington, D.C., while cities in Nebraska and Kentucky receive increases of about 40%. The document that outlines the grants says that New York City has “no national monuments or icons.”
- Soda Companies to Limit Sweet Drinks Sold in Schools (May 3): Coca-Cola, PepsiCo Inc., and Cadbury Schweppes agree to remove sweetened sodas and other drinks from schools by 2009.
- New England Flooded by Record Rains (May 16): Nearly 13 inches of rain fall over eight days in much of New England, causing the region's worst flooding in 70 years.
- Enron Executives Are Convicted (May 25): Kenneth Lay and Jeffrey Skilling, former chief executives of Enron, are found guilty of fraud and conspiracy by a Houston jury. Lay is convicted of six counts of fraud and conspiracy and four counts of bank fraud. Skilling is found guilty of 18 counts of fraud and conspiracy and one count of insider trading.
- Thousands Die in Indonesian Earthquake (May 27): About 5,750 people are killed in a 6.3 magnitude earthquake on Java Island. Nearly 500,000 are left homeless.