US forces destroyed the former base of counter-ISIS operations in Syria, according to a release from Operation Inherent Resolve sent out on Wednesday.

The statement says that the operation was pre-planned, but former Special Presidential Envoy to the Global Coalition to Defeat ISIS Brett McGurk called the operation a "break glass" procedure used only in extreme emergencies.

US President Donald Trump's hasty decision to pull US troops out of northeastern Syria last Sunday continued to spiral out of control when, a week after Turkey began its incursion into the region, US forces attacked the base of their counter-ISIS operations in Syria in a move one former official called a "break glass" procedure "reserved for an extreme worst-case scenario."

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On Wednesday, US troops vacated the LaFarge Cement Factory base, which they shared with Kurdish-led Syrian Democratic Forces (SDF) fighters. The SDF fighters lit their area on fire and left, according to reports, and US troops threatened oncoming Turkish-backed forces with Apache helicopters and F-15E fighter aircraft in a show of force.

When that failed to stop the forces' advance, the US troops withdrew, and two F-15Es attacked the base in a "pre-planned" attempt to destroy munitions and other supplies inside and limit the "facility's military usefulness," according to Col. Myles B. Caggins, a spokesperson for Operation Inherent Resolve, the US's anti-ISIS operation.

Brett McGurk, the former Special Presidential Envoy for the Global Coalition to Counter ISIS under Trump and former President Barack Obama, tweeted Wednesday that the attack on the facility was an "emergency 'break glass' evacuation procedure reserved for an extreme worst-case scenario."

Insider reached out to the Department of Defense with questions regarding whether the US planned to destroy other bases, and whether the destruction of the LaFarge Cement Factory base was normal operating procedure, but the DoD did not respond to Insider's query by publication time.

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The US does destroy equipment such as vehicles that it does not want in the hands of adversaries and does not have the capability to remove. According to CNN, the attack Wednesday was the first known instance in which US forces have destroyed equipment during the withdrawal from Syria.

Rep. Mark Pocan, a Democrat from Wisconsin and a member of the House Appropriations Committee, submitted a letter to Secretary of Defense Mark Esper on Thursday requesting more information about the destruction and abandonment of US military facilities and equipment in Syria. In the letter, Pocan referred to Trump's withdrawal as "reckless" and warned against "poor decision-making while withdrawing troops from current conflicts or spending American taxpayer dollars in a foolish manner."

A spokesperson for Pocan told Insider that his office learned of the air strike from a CNN report and "there was not enough information" about what happened and the decision making around it.

"This is clearly a part of a snowballing effect of the president's policy in Syria," he said — a policy that has "no intentionality or organization."

The spokesperson said Pocan's office had not yet received a response to the letter.