ST LOUIS, MO - OCTOBER 09: Democratic presidential nominee former Secretary of State Hillary Clinton responds to a question during the town hall debate at Washington University on October 9, 2016 in St Louis, Missouri. This is the second of three presidential debates scheduled prior to the November 8th election. (Photo by Rick Wilking-Pool/Getty Images)

Democratic presidential nominee Hillary Clinton responds to a question during the town hall debate at Washington University on Oct. 9, 2016, in St. Louis, Missouri.

Photo: Rick Wilking/Getty Images

Hillary Clinton claimed she is staunchly opposed to sending American ground troops to Syria, calling it a “very serious mistake.” But her plan for civilian “safe zones” would require tens of thousands of American ground troops.

Military experts agree the U.S. could not defend safe zones from the air. Secretary of State John Kerry told a Senate panel in February that the Pentagon estimated it would require between 15,000 and 30,000 American troops — nearly doubling the number of “boots on the ground” in the Middle East.

Clinton has never addressed the contradiction between her renunciation of ground troops in Syria and her call for safe zones.