Wallace noted on "America's Newsroom" that previous cease-fires in Syria between the Assad regime and opposition forces were short-lived, as reports indicated the new one in northern Syria was already in question.
"The bigger question is: Is this a cease-fire or is this a surrender that's been negotiated by the U.S.?" said Wallace.
Journalists have reported continued fighting in the Syrian town of Ras al-Ayn on Friday morning, while other areas have reported relative calm since the agreement.
President Trump declared Thursday "a great day for civilization" as Vice President Mike Pence and Secretary of State Mike Pompeo announced terms of a cease-fire agreement that would end violence between Turkey and Kurds in Syria, following a meeting with Turkish President Recep Tayyip Erdogan in Ankara.
The deal is for a 120-hour cease-fire, during which time the Kurdish-led forces could pull back from the roughly 20-mile-wide safe zone on the Turkish-Syrian border. All Turkish military operations under the recent offensive known as Operation Peace Spring will pause during that time, and the operation itself will come to an end entirely upon the completion of the Kurdish withdrawal, under the terms of the deal.
Trump tweeted Friday that he spoke to Erdogan, who told him "there was minor sniper and mortar fire that was quickly eliminated. He very much wants the ceasefire, or pause, to work."
Wallace explained that the size of the negotiated buffer zone is an "enormous area" that is 280 miles wide. He said hundreds of thousands of Kurds have lived in the area for generations.
"Even if the deal holds, all of those Kurds would have to pull back from that area," Wallace said.
"Where would they go, how would they live? All of that is unstated," he said, questioning whether Kurdish fighters plan to vacate the area permanently.
He said another big question is whether Turkish-backed militias, blamed for murdering Kurdish civilians during the recent invasion, will abide by the cease-fire.