It's been less than 12 hours since the United States, together with its French and British allies, launched a major series of standoff strikes against sites connected to the Syrian government's chemical weapons arsenal. Our unique marathon coverage detailed these events moment-by-moment. The Pentagon has now provided additional information in a more comprehensive briefing.

Here are the major details from the brief: - Pentagon chief spokesperson Dana White insisted that "this operation does not represent a change in US policy" and was not an attempt to unseat Assad or become involved in the Syrian Civil War. - It was a response to the Assad regime’s “illegal tactics” in continuing to use chemical weapons and reflected a moral imperative to intervene. - U.S. Marine Corps Lieutenant General Kenneth McKenzie, the Director of the Joint Staff, said the Syrians had been unable to have any “material interference” in the operation and all the missiles reached their targets. - McKenzie said there had been no indication of a military response from "actors" within Syria, but that American troops in the country remained ready to defend themselves. - He described the mission, which was coordinated so that the 105 total standoff weapons all hit their targets around 4 AM local time in Syria, as “precise, overwhelming, effective." - The operation “significantly crippled” Syria’s chemical weapons capabilities and despite reports of evacuations of some production equipment and other materiel, some fixtures were likely too large to move to another, safe location. - 76 missiles struck the Barzah Research Center in Damascus, including 57 Tomahawk Land Attack Cruise Missiles (TLAM) and 19 Joint Air-to-Surface Standoff Missile-Extended Range (JASSM-ER) air-launched cruise missiles.

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- 22 missiles impacted the chemical weapon storage facility west of Homs, including nine TLAMs - all from U.S. ships - eight Storm Shadow air-launched cruise missiles from UK aircraft, three Missile de Croisière Naval (MdCN) cruise missiles from French frigates, and two SCALP air-launched cruise missiles from French aircraft.

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- Seven French SCALP missiles hit the associated bunker complex near the second target.

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Naval assets included the U.S. Navy's Virginia-class submarine USS John Warner, the Ticonderoga-class cruiser USS Monterey, and the Arleigh Burke-class destroyers USS Higgins and Laboon. - The Laboon and Monterey engaged targets from the Red Sea, Higgins fired missiles from the North Arabian Gulf, and John Warner was in the Mediterranean Sea. - In total, Monterey launched 30 TLAMs, Higgins launched 23, Laboon launched seven, and John Warner launched six. - The French Aquitaine-class frigate Languedoc also took part in the operation from the Mediterranean. - Air assets operated from bases throughout the region included US Air Force B-1B bombers, which fired all 19 JASSM-ER missiles, escorted by Air Force fighter jets.

- UK Tornado GR4 jet combat aircraft and French Rafale and Mirage 2000 multi-role fighter jets also took part. The UK and France committed unspecified escorting fighter jets. - American defensive counter air packages were still flying sorties at the time of the briefing. - Lieutenant General McKenzie said the Syrians attempted to shoot down incoming missiles with 40 surface-to-air missiles using a "ballistic trajectory" and "without guidance." - He added that those missiles “had to come down somewhere” and posed a danger to innocent bystanders.

DoD This image gives a basic idea of the vectors of attack and the parties involved in the strike but is not representative of the number or types of platforms used.

- McKenzie said the loss of the facilities would be significant for Assad, but declined to offer a more granular description about the residual status of the Syrian government's chemical capabilities. - He did acknowledge that there still could be Syrian government chemical weapons attacks in the future and that there were additional chemical weapons related sites that the U.S. and its partners did not hit. - The general declined to elaborate on the other alternatives the U.S. military presented to the Trump administration, which ultimately decided to pursue this particular strike package. - Dana White stressed that the operation was different from the strike on Syria’s Shayrat Air Base and focused on neutering Assad’s chemical weapons production capability rather than delivery platforms. - Dana White declined repeatedly to elaborate on any evidence the United States had that the Syrian government had conducted the chemical weapon attack in Douma and what agents it used and said the U.S. government was still assessing the situation. - She did say the U.S. government remained "confident" that there had been a chemical weapon attack and the Syrian government was responsible. - McKenzie said that the U.S. military conducted a detailed targeting process, including "plume analysis" and other tasks, in order to mitigate the possible release of chemical agents from the strikes on any of the three sites. - He would not say if the U.S. military had conducted any post-attack air sampling, only that the post-strike assessments were coming through "a variety of means. - The deconfliction line with the Russians remains active, but McKenzie would not say if there had been any discussions via that communications line regarding the strikes specifically. - Dana White put the onus on Assad, as well as his Russian and Iranian benefactors, in whether or not the United States would feel compelled to act again in response to another chemical weapon attack. - She said the Russian-sponsored Sochi peace plan "has failed" and that the United States remained committed to the United Nations-backed Geneva peace process to end the country's civil war. - The U.S. government also noted that there had been a noted uptick in Russian-enabled disinformation regarding the situation in Syria in the aftermath of the strikes.