Former Defense Secretary James Mattis, who led the Pentagon through the first two years of the Trump administration, warned during an exclusive interview with NBC's "Meet the Press" that the president's decision to pull troops from Syria's border in advance of a Turkish incursion could have dire consequences and lead to ISIS's resurgence.
"We have got to keep the pressure on ISIS so they don't recover," Mattis said in response to "Meet the Press" moderator Chuck Todd's asking whether the United States would regret Trump's decision.
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"We may want a war over; we may even declare it over. You can pull your troops out as President Obama learned the hard way out of Iraq, but the 'enemy gets the vote', we say in the military. And in this case, if we don't keep the pressure on, then ISIS will resurge. It's absolutely a given that they will come back."
Trump announced the decision to move U.S. forces from the region of northern Syria bordering Turkey on Sunday, stating that Turkey wanted to begin an operation in the region to resettle Syrian refugees.
The announcement drew widespread and intense criticism, including from some of Trump's Republican colleagues, because Turkey's offensive is against Kurdish-led Syrian Democratic Forces (SDF), who have been a key U.S. ally in the fight against ISIS.
Mustafa Bali, the official SDF spokesperson, has told NBC News the U.S. decision to stand aside as Turkey moves into Syria was "shocking and unexpected." Bali called it "a huge mistake" that will allow ISIS to "reunite itself and appear again stronger than before."
"It seems that the policy of the United States is to betray their friends and allies," Bali added.
The Trump administration announced Friday that it was prepared to slap stiff economic sanctions on Turkey in response to the country's military offensive.
A day before, Trump defended his decision by stating on Twitter that he was "trying to end the ENDLESS WARS."
"Turkey has been planning to attack the Kurds for a long time. They have been fighting forever. We have no soldiers or Military anywhere near the attack area. I am trying to end the ENDLESS WARS," the president said.
Trump said in an additional series of tweets that the United States had "defeated 100% of the ISIS Caliphate."
"We did our job perfectly!" he wrote.
Mattis, a retired Marine Corps general who led U.S. Central Command and served in the Gulf War, and the wars in Afghanistan and Iraq, did not seem convinced.
"It’s in a situation of disarray right now," Mattis told Todd. "Obviously, the Kurds are adapting to the Turkish attacks. And we'll have to see if they're able to maintain the fight against ISIS. It's going to have an impact. The question is, how much?"