(WASHINGTON) — A senior American diplomat has written a highly critical assessment of the Trump administration’s abrupt withdrawal of troops from northeast Syria last month, a decision that paved the way for an attack on U.S.-allied forces in the area, officials said Thursday.

In an internal memo, William Roebuck, the top American diplomat in northern Syria, takes the Trump administration to task for not doing more to prevent Turkey’s invasion or protect the Kurds, who fought alongside U.S. forces in the battle against the Islamic State group, according to two U.S. officials familiar with the matter.

One of the officials described the memo, which was obtained and first revealed by The New York Times, as “lengthy and harsh.” The officials were not authorized to discuss internal documents publicly and spoke on condition of anonymity.

Roebuck’s memo highlights how Trump’s decision to withdraw American troops was deeply divisive, even within his own administration. The move was widely criticized by Democrats and Republicans as abandoning a key ally in the fight against the Islamic State.

Related Stories

Politics

U.S. Extends Civil Nuclear Cooperation Waivers for Iran