The US has to dramatically change its approach to North Korea

• President Trump's dysfunctional diplomacy when it comes to North Korea and other nations has to stop or the damage could be severe.
• It is clear that North Korean President Kim Jong-un's motive isn't to launch nuclear war but to have the ability to deter an attack from a powerful rival like the U.S.
• If the U.S. doesn't change its approach, the best outcome is perpetual frustration and the worst is nuclear war.

Toru Hanai | Reuters

People walk past a street monitor showing news of North Korea's intercontinental ballistic missile test in Tokyo, Japan, July 4, 2017.

As his Secretary of State was negotiating with China in an effort to find a way to lower tensions with North Korea, President Trump undercut the nation's top diplomat tweeting that he was "wasting his time" engaging in mediation. This is one – but far from the only – example of dysfunctional diplomacy afflicting the administration. If not soon corrected, the damage done to the country could be severe.

For months, the administration has been trying to apply enough pressure on North Korean dictator Kim Jong-un to force him into giving up his nuclear weapons program. A common refrain among the many so-called experts weighing in on why Kim stubbornly refuses to give up his nukes is that the reclusive dictator is irrational, arrogant, or just plain crazy. This much is certain: Kim is a brutal, murderous, and vicious leader. He is not, however, suicidal, and is in fact acting quite rationally based on his worldview.

Fundamentally, looking at situations from another's perspective does not condone their actions, does not concede any of their points, nor acknowledge their views are valid. But when negotiating with any partner—and especially an adversary—it is critical we understand what motivates their actions, what they fear, and what they desire.

It is instructive to determine why the Kim dictators have pursued nuclear weapons so emphatically. First, the reason isn't to gain the ability to attack American cities or personnel in an offensive strike. Their overriding and unambiguous purpose is to provide the regime with the ability to deter invasion and attack from its much stronger neighbors and the U.S., a country with which it warred in the 1950s at great cost.

Given recent history, they believe they must possess a credible, deliverable nuclear weapon to prevent the U.S. from ever invading or trying to change the regime by force. We don't have to wonder what North Korea's foreign policy objectives are in this current standoff, as their official news agency has plainly stated: "Our final goal is to establish the equilibrium of real force with the U.S. and make the U.S. rulers dare not talk about military option for the DPRK."

Perhaps the biggest impediment to solving this predicament with North Korea is not President Trump's decidedly undiplomatic behavior—though this clearly narrows our available policy options—but on the myopic foreign policy actions U.S. leaders have taken generally over the past several decades, and in the past few years in particular. One of the drivers of North Korean fears is their assessment of U.S. foreign policy practiced on Libya.

In December 2003, the Bush administration negotiated a deal with Libyan dictator Muammar Gaddafi to disband its nuclear weapons program in exchange for various economic and security promises. The process was effectively completed in 2009—but two years later, the international community, aided by President Obama, deemed Gaddafi a menace and ordered airstrikes that brought his regime down, and the Libyan leader was later killed in the streets.

This decision continues to hamstring American efforts abroad to this day.

Kim is convinced that should he ever give up his nuclear deterrent, a day will come when we decide to attack him—and without nuclear weapons to deter us, he'll be vulnerable.

If Washington policymakers believe that making life harder for the North Koreans is going to force them to submit to U.S. pressure and give up the only deterrent they believe can ensure their survival, we doom our policy to failure before it even begins—an increasingly recurrent theme.

If the administration doesn't change course, the best outcome we could hope for regarding North Korean is perpetual frustration at our inability to accomplish security objectives; the worst case is a nuclear war leading to the deaths of millions of South Koreans, Japanese, and Americans in the region.

Dramatic and immediate changes in the way America conducts foreign policy must be made. We have to examine and understand the viewpoint of our friends and adversaries and then propose and pursue policy solutions that can rationally be accomplished—and then hold true to our word. Neglecting to do so puts us on a path to long-term failure.

Commentary by Daniel L. Davis, a senior fellow for Defense Priorities and a former Lt. Col. in the U.S. Army who retired in 2015 after 21 years, including four combat deployments. Follow him on Twitter @DanielLDavis1.

For more insight from CNBC contributors, follow @CNBCopinion on Twitter.