Retired Army Lt. General Mark Hertling said that Donald Trump's plan to defeat ISIS shows "a complete lack of understanding of the threat and the ways to fight it."
Hertling made the comments during an appearance on CNN's "Anderson Cooper 360."
Trump discussed his plan to defeat ISIS at a Greenville, NC rally. According to ABC News, Trump said that on the first day of his presidency, he would meet with his top generals.
"They will have 30 days to submit to the Oval Office a plan for soundly and quickly defeating ISIS. We have no choice," Trump said.
About Trump's plan, Hertling told Anderson Cooper, "I had to ask myself, what the hell does he think we've been trying to do for the last 14 years, in terms of al-Qaida?"
"It's a sophomoric approach to elements of national security policy, because if he's just calling in the military, he's missing the point that there's several other elements of national security that will help defeat ISIS," he said.
"This is a generational threat. You don't just say, 'Beat it in 30 days," Hertling said.
Hertling said that the Trump's plan was "insulting to the individuals who had been attempting to put all their strength on the line to defeat it."
Hertling responded to critics that say the U.S.'s armed forces feel hamstrung by budgets or politics, and "have their hands tied behind their backs." Hertling rejected that idea, and said that he had spoken to generals in the field, and they do not feel that way.
"The leaders aren't claiming that their hands are tied behind their backs. They are going after these individuals with a vengeance, with special operations forces, with intelligence collection," Hertling said.
Hertling blasted an announcement by 88 generals that they are endorsing Trump. He said many of the names on the list were Navy admirals who had no experience fighting against terrorists.