Fro the WaPo's summary:
The ease with which the demonstrators reached the embassy underscored, however, how little sway the United States now has over the Iraqi government it installed after 2003 and the security forces it trained.
The embassy compound lies inside the Green Zone, which is normally off limits to ordinary people. But thousands walked unimpeded into the zone to participate in the embassy assault. Iraqi security forces mingled with the crowd, and some joined in. One member of the force that guards the zone’s checkpoints was photographed helping militia supporters smash the bulletproof glass at the embassy reception gate.
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the demonstrators . . . smashed their way into one of the facility’s heavily guarded reception areas, breaking down armored doors and bulletproof glass before setting fire to the room.
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The demonstrators also smashed security cameras, set two guardrooms ablaze and burned tires. They made a bonfire out of a pile of papers and military MREs (meals ready to eat) found in the reception area, where guards normally search and X-ray visitors.
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The U.S. diplomats and embassy staffers inside the safe room felt secure, according to two reached by a messaging app. They declined to give details.
It was unclear how many U.S. officials were in the compound. Officials have given different estimates of the number of American full-time staffers in Iraq, ranging from 300 to 352, but have not provided a breakdown of their locations.
U.S. Ambassador Matt Tueller is out of the country on previously scheduled personal travel
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as the day wore on it became increasingly unclear whether the United States could safely retain a diplomatic and military presence in Iraq without embarking on a wholesale confrontation with the militia — and its Iranian backers — now effectively besieging the embassy.
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Among the crowd were some of Iran’s most powerful allies in Iraq, including Hadi al-Amiri, leader of the Badr Organization; Qais al-Khazali, who heads the Asaib Ahl al-Haq militia and was once imprisoned by the U.S. military; and Jamal Jaafar Ibrahimi, better known by his nom de guerre, Abu Mahdi al-Mohandes, who spent years in prison in Kuwait for bombing the U.S. Embassy there.
WATCH: Thousands of Iraqi protesters furious over deadly U.S. airstrikes storm the American Embassy in Baghdad, breaking down doors and setting fires https://t.co/zS7HQXjDyF pic.twitter.com/MO3UnaG06q— CBS News (@CBSNews) December 31, 2019
#Breaking: Just in - Reports that #Hezbollah supporters are burning the back wall outside the #US embassy in #Baghdad's green zone in #Iraq, and are willing to storm inside the building to destroy everything inside. pic.twitter.com/LbFpURqTjX— Sotiri Dimpinoudis (@sotiridi) December 31, 2019
Kataib Hizbulla militia and PMF protesters and U.S embassy guards are separated by a glass barrier pic.twitter.com/JJyUR7ySee— Steven nabil (@thestevennabil) December 31, 2019
VIDEO: AH-64 Apaches protect @USEmbBaghdad. ๐“We have taken appropriate force protection actions to ensure the safety of American citizens...and to ensure our right of self-defense. We are sending additional forces to support our personnel at the Embassy.”~@EsperDoD ๐บ๐ธ๐ฎ๐ถ pic.twitter.com/amABHBAOcL— OIR Spokesman Col. Myles B. Caggins III (@OIRSpox) December 31, 2019
VIDEO: #HappyNewYear! Rapid deployment! Last night, #Marines flew to Baghdad in Ospreys on to protect staff & facilities. ๐ช๐ป๐ช๐ผ๐ช๐พ ูุง ููุฑูุนุฉ ...ุงูุธุฑูุง ู ู ุงูุฐู ุญูู ู ุน ุทููุฑ ุงููุนุงู ููุนุงู ุงูุฌุฏูุฏ ! ุงููู ููุงุช ุงูู ุดุงุฉ ุงูุจุญุฑูุฉ ุงูุงู ูุฑููุฉ ูู ุจุบุฏุงุฏ ุฃุชูุง ูุญู ุงูุฉ ุงูู ูุดุขุช ูุงูู ูุธููู. ุฃููุง ุจูู . pic.twitter.com/8yKtZ8d74p— OIR Spokesman Col. Myles B. Caggins III (@OIRSpox) January 1, 2020