The US military isn't in any position right now to strike North Korea with the kind of campaign that would be needed to bring battlefield success and would need weeks, if not months, to sort out the logistics, analysts say.
Mark Hertling, a retired US Army general and CNN analyst, said the tens of thousands of US civilians, many of them military dependents, would first need to be evacuated from South Korea.
The US would also need to add to its forces in the region in what Hertling called "a reinforcement of shooters." These would include US Navy ships and submarines armed with cruise missiles, plus Air Force bombers that could operate out of bases in Japan or Guam, he said.
"Some of these are in places in the region, but not enough to decapitate North Korea in terms of their artillery," Hertling said.
North Korea has thousands of conventional artillery pieces within range of the South Korean capital of Seoul. Studies have estimated South Korean casualties from artillery barrages to be in the tens of thousands on the first day of conflict.
Hertling says a couple of weeks of airstrikes would be needed to take out that artillery. And the US would need the planes, bombs, fuel and support personnel in place to carry out that campaign, he said, comparing it to the country's Desert Storm operation against Saddam Hussein's Iraq in 1991.
In Desert Storm, the US-led coalition began its bombing campaign against Iraq more than five months after hostilities began with Iraq's invasion of Kuwait.
As with Desert Storm, it would take weeks to get needed US Army tanks and ground troops from the bases in the US to ports in southern South Korea and even longer to get them north to where they'd be in a fight with North Korea, said Hertling, who participated in those kinds of simulations on the Korean Peninsula.
Hertling also said at least two US Navy aircraft carrier strike groups would need to be in the waters near Korea before any US attack.
Carl Schuster, a former director of operations at the US Pacific Command's Joint Intelligence Center, said there should be even more US firepower.
"As a planner, I'd rather have three carriers than two," plus additional Air Force, Navy and Marine Corps fighters, said Schuster, now a Hawaii Pacific University professor.
Schuster also said the US would need to ensure it had enough bombs, missiles and electronic warfare planes to destroy or disable North Korea's air defenses before the heavy bombers needed to strike North Korea's fortified nuclear weapons sites could be sent in. Reinforcements for those aircraft would likely have to be dispatched to Guam or Japan.
Hertling said much of what the US would need may not even be stationed in the US, but deployed in current military campaigns against ISIS in the Middle East or the Taliban in Afghanistan.
All that being said, Schuster said it wouldn't be surprising to see some US assets moving nearer to the Korean Peninsula in the next few days, maybe a carrier group into waters close to Japan, another guided-missile submarine port call
in South Korea, or more US Air Force bombers moving to Guam or Okinawa.
But these would be defensive in nature and more of a warning to Pyongyang rather than indications that a US strike was imminent, he said.
As well as that, he said he expects US diplomats to be more visible, including Secretary of State Rex Tillerson, who has been visiting countries in Southeast Asia this week.
"This will force Tillerson to be a bit more visible," Schuster said of comments by Trump on Tuesday that North Korea will see the US's "fire and fury."
"He's going to get a lot of questions of what our intentions are," Schuster said.
Schuster also said he doesn't expect any North Korean attack on Guam or any place else, saying Kim Jong Un's threats are mostly bluster.
"Kim's actions are macho within some concise constraints," he said.
One, North Korea's missiles are untested in actual battle and their accuracy is far from certain, he said.
Two, "the US could retaliate in a fashion Kim couldn't withstand," meaning the end of the Kim regime, he said. "He does not want to provoke us into something that would remove him from the scene."
But Kim is a wily operator and knows what he can get away with, so another missile test or large-scale artillery exercises in North Korea wouldn't be surprising, added Schuster.
"Launching a missile at Guam is not something he can get away with. Launching a test missile sends the same message domestically and internationally," said Schuster.
And another missile test is far short of war. As Schuster points out: "There's a big gap between bombast and action."