Even if that's a possibility, analysts say the US is in no position right now to wage the kind of military campaign that could bring battlefield success on the Korean Peninsula. It would need weeks, if not months, to get needed additional troops and equipment to the region.
Those would include aircraft such as B-2 and B-52 bombers that would operate out of the US Air Force base on Guam, and F-22 stealth fighters would be part of any first strike, experts say.
Additional warships and submarines equipped with Tomahawk missiles would be needed to suppress North Korean air defenses so the bombers could operate, they say.
And then ground troops would be needed in far greater numbers that are now available to take control of sites inside North Korea where nuclear weapons might survive a first strike.
"No additional forces are present," Schuster said Monday.
But the US does have the forces such as the THAAD and Aegis missile defense systems in place to protect South Korea and Japan from a North Korean first strike, Hertling said.
And that means there's still time to get diplomacy to work, he said.
"We're still controlling the clock here. It's within our ability to keep the initiative," he said.