Decorated U.S. Army veteran Daniel Davis says he's "concerned" that the United States is not backing down from its threat of military action against North Korea.
"That has virtually no chance of success," Lt. Col. Davis told CNBC's "The Rundown," as world leaders head to the United Nations in New York this week to further discuss an international response to North Korea's aggressive nuclear weapons program.
Military options, he said, should "unequivocally" be taken off the table: "That time had passed."
Part of the problem, Davis said, is that "you cannot wipe out all of their ability to fire weapons of mass destruction" fast enough to prevent a counterattack from Pyongyang.
"All you can do is to make him [North Korean leader Kim Jong Un] believe with a military strike that we are coming after him, and now he has incentive to use these weapons," he said.
Davis retired from the U.S. Army after 21 years of active service and is now a senior fellow and military expert at Defense Priorities, a think tank.
U.S. Ambassador to the United Nations Nikki Haley said the United Nations Security Council had "run out of options" on containing North Korea, and the United States may have to turn the matter over to the Pentagon.
For Davis, that's a clear escalation of rhetoric.
"We want to give him no incentive to use the weapons, and that's why deterrence is such a critical thing at this point in time," he said. "We can't think that sanctions are going to stop him from what he's doing. We have to find other levers, and I don't even think we're looking for those right now."
Defying a fresh round of tough new UN Security Council sanctions on its textile exports and crude oil imports, North Korea launched a missile over Japan into the Pacific Ocean last week, prompting international condemnation.
"It's not as if they decided to launch a test missile after the UN sanctions last Monday," Davis said. "What's going on is part of a broader process."
"They need to launch a good four to five additional missiles over the next 12 months, with three to four months between each one of them, so they can validate the effectiveness of their missile fleet," he added.
Pyongyang's objective, Davis said, is to have a reliable ballistic missile capability so it can defend itself from what leaders view as the threat of a U.S. attack.
"We can expect more missile launches," he said.