WASHINGTON (AP) -- To congressional Republicans, "Benghazi" is shorthand for incompetence and cover-up. Democrats hear it as the hollow sound of pointless investigations.
It is, in fact, a Mediterranean port city in Libya that was the site of an attack on an American diplomatic compound on the 11th anniversary of 9/11 that killed U.S. Ambassador Chris Stevens and three other Americans. That's nearly all that U.S. politicians can agree on about Benghazi.
It's been a political rallying cry since just weeks before President Barack Obama's re-election in November 2012. With the launch of a new House investigation, Benghazi is shaping up as a byword of this fall's midterm election and the presidential race in 2016, especially if former Secretary of State Hillary Rodham Clinton is on the ballot.
The administration on Tuesday heralded its first arrest in the case: Ahmed Abu Khatallah, a senior leader of the Benghazi branch of the terror group Ansar al-Shariah in Libya, who was being held at an undisclosed location outside Libya.
A guide to the controversy:
SETTING THE SCENE
The 2011 revolt that deposed and killed Libyan dictator Moammar Gadhafi, with the help of NATO warships and planes, began in Benghazi. A year later, the city of 1 million remained chaotic, in the grip of heavily armed militias and Islamist militants, some with links to al-Qaida.
The temporary U.S. diplomatic mission, created to build ties and encourage stability and democracy, was struck by homemade bombs twice in the spring of 2012. British diplomats, the Red Cross and other Westerners were targeted that spring and summer.
Stevens, based in the capital city of Tripoli, chose to visit Benghazi on the anniversary of the Sept. 11, 2001, attacks, when U.S. embassies around the world were on alert for terrorism.
In Egypt that day, a different sort of trouble struck, trouble that would spread to other Mideast cities over several days: Protesters angry about an anti-Muslim video made in America stormed the U.S. Embassy in Cairo, clambering over the walls and setting flags on fire.
Hours later, the assault in Benghazi began.
A FIERY ASSAULT AND FOUR DEATHS
The Benghazi attack came in three waves, spread over eight hours at two locations.
According to accounts from congressional investigators and the State Department's Accountability Review Board:
Around 9:40 p.m., a few attackers scaled the wall of the diplomatic post and opened the front gate, allowing dozens of armed men in. Local Libyan security guards fled. A U.S. security officer shepherded Stevens and Sean Smith, a State Department communications specialist, into a fortified "safe room" in the main building.
Attackers set the building and its furniture afire with diesel fuel. Stevens and Smith were overcome by blinding, choking smoke that prevented security officers from reaching them. Libyan civilians found Stevens in the wreckage hours later and took him to a hospital, where he, like Smith, died of smoke inhalation.
Stevens was the first U.S. ambassador to be killed in the line of duty in more than 30 years.
A security team from the CIA annex about a mile away arrived to help about 25 minutes into the attack, armed only with rifles and handguns. The U.S. personnel fled with Smith's body back to the annex in armored vehicles.
Hours after the first attack ended, the annex was twice targeted by early morning mortar fire. The second round killed Tyrone Woods and Glen Doherty, two CIA security contractors who were defending the annex from the rooftop.
A team of six security officials summoned from Tripoli and a Libyan military unit helped evacuate the remaining U.S. personnel on the site to the airport and out of Benghazi.
THE FALLOUT BACK HOME
Word hit Washington in the final weeks of the presidential race. Over the next several days, the Benghazi news blended with images of angry anti-American demonstrations and flag-burnings spreading across the Middle East over the offensive video.
Political reaction to the Benghazi attack quickly formed along partisan lines that hold fast to this day.
Republican presidential nominee Mitt Romney and others said Obama had emboldened Islamic extremists by being weak against terrorism. But the public still credited Obama with the successful strike against al-Qaida leader Osama bin Laden a few months earlier in Pakistan.
The accusation that took hold was a Republican charge that the White House intentionally misled voters by portraying the Benghazi assault as one of the many protests over the video, instead of a calculated terrorist attack under his watch.
Obama accused the Republicans of politicizing a national tragedy. He insists that the narrative about the video protests was the best information available at the time.