Secretary of State Rex Tillerson Rex Wayne TillersonGary Cohn: 'I haven't made up my mind' on vote for president in November Kushner says 'Alice in Wonderland' describes Trump presidency: Woodward book Conspicuous by their absence from the Republican Convention MORE said Friday that “all options are on the table” to deter the threat from Pyongyang. What does that really mean? Is the use of military force really an option?

How to interpret that depends on who you are. Is that comment just a part of a continuing pattern of the U.S. response to escalation of both North Korea’s capability and rhetoric for the past two administrations?

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What usually follows now is North Korea will conduct another ballistic missile test, or even a nuclear test — either way, we can expect a response from Kim Jong-un to these remarks by Secretary Tillerson. Countries in the region will respond and have — the Japanese are taking about developing first strike weapons; South Korea is pushing the U.S. to return tactical nuclear weapons to their military capability; the Chinese hold a key leverage with their economic lifeline to the regime, all in spite of UN sanctions.

If you are an ally of the U.S., especially those in the region, you might want begin taking inventory of your military capability. The question remains — is the military option really on the table? Would South Korea and others in the region actually green light a military operation, which could cause immediate casualties and destruction the world hasn’t seen since WWII? What are the parameters of a successful military operation?

First, a war with North Korea would take extensive planning, coordinating, rehearsing and preposition of military assets. A first strike would have to be a complete surprise to be successful — mainly because the Korean leader has watched twice in the past 20 years the U.S. build up to go to war, then pull the trigger both times.

In what would be a nothing-to-lose proposition, North Korea could first strike the South and inflict incredible damage with their nuclear arsenal — and they have even stated they would do this. In today’s interconnected world, the likelihood of any surprise military action is remote.

Tillerson: Military action against North Korea "on the table" https://t.co/x5a5S1xuGP pic.twitter.com/0iQWLJzCdB — The Hill (@thehill) March 17, 2017

In order to be successful, any military action against North Korea would have to amount to the largest full scale attack that world hasn’t seen since D-Day. It would have to be updated to reflect current capability, but would have to come from all sides — air, land, sea, and a new domain, cyber.

The attack would likely start with a cyber attack, looking to shut down all communications and utilities on the scale the world hasn’t never seen. On the traditional military side, to be effective the initial assault would have to destroy any and all nuclear first strike capability of the North Koreans. We would have to literally blanket the sky for hours with air strikes on their nuclear facilities, as well as other military targets.

We would have to hunt down their mobile launchers, which can be hidden in their mountainous regions — then be ready to shoot down a missile if they get one off. We would have to ferociously strike military targets along the border, where artillery tubes in range could reign down conventional munitions to the millions of residents of Seoul. The attack would not focus on just military targets — there would be civilian casualties in the hundreds of thousands as well.

Report: Tillerson cuts short South Korean visit, citing "fatigue" https://t.co/aZpqsB3hGX pic.twitter.com/BFJqAGglXJ — The Hill (@thehill) March 17, 2017

U.S. and South Korean ground troops would be on full alert, and likely on the defense to the north to thwart a potential ground attack from the Korean People’s Army (KPA). There would be a focus to defend attacks from tunnels prepared by the KPA for this very likelihood. The U.S. would have to be prepared to send troops to South Korea at the onset of hostilities — at least 50,000 troops to reinforce the defense and potentially go on the offensive.

Unfortunately, the war won’t go as planned for many reasons — if the North is successful in launching a nuclear weapon that destroys part of Seoul, that would change the calculus of our counter response. I don’t see the U.S. side using nuclear weapons in the initial barrage, but would surely retain the option to use them in response.

Military planners need to figure out what is the true capability of the North Korean military, and in particular their first strike capability, and be right about it. We know they have a nuclear weapon, but can they deliver it accurately and in a manner that doesn’t kill its own people? Until the world is ready to accept casualties on the level of what was seen in Europe and Asia in the Second World War, the military option is really not on the table.

Army Major Mike Lyons (Ret.) is a Senior Fellow with the Truman National Security Project and is a military analyst for CBS News.

The views expressed by contributors are their own and not the views of The Hill.