If President Trump goes ahead with announced plans to meet with North Korean dictator Kim Jong Un, he would open the door to potentially solving our nuclear dispute with the Communist nation short of war. This is a far better course that listening to the calls from some to give up on diplomacy and use military force against the North.

Former U.S. Ambassador to the United Nations John Bolton, for example, recently put forth an argument – echoed by a number of establishment foreign policy members – that America was legally justified in conducting a preventive military strike on North Korea.

But the case that a military attack on the North is necessary and would be effective is both flawed and wrong. Such a drastic and costly course of action should only be taken as an absolute last resort to forestall an imminent attack by North Korea.

Bolton claimed that those who oppose striking in the absence of a North Korean attack “argue that action is not justified because Pyongyang does not constitute an ‘imminent threat.’ They are wrong. The threat is imminent.”

Bolton added that the U.S. “should not wait until the very last minute.” Otherwise, he continued, we “risk striking after the North has deliverable nuclear weapons, a much more dangerous situation.”

If such a U.S. strike were ordered, it would have catastrophic consequences for us. Far from ensuring our safety, it would impose egregious levels of casualties on U.S. forces and American civilians, and harm – not help – our security and our prosperity.

Also critical is the fact that only Congress can authorize such a strike. Subsection 2(c) of the War Powers Resolution of 1973 expressly limits the president’s ability to use military force abroad under only three conditions: First, when Congress has declared war; second, when Congress has specifically authorized such action; or third, during a national emergency “created by (an) attack upon the United States, its territories or possessions, or its armed forces.”

There is nothing in the law that authorizes the president to use lethal military force against an adversary merely because it possess a capability to attack us. Absent an actual or imminent attack, such use would violate U.S. and international law.

Though the Constitution prevents the president from taking such unlawful actions, there is also a very practical reason for refusing to do so: It isn’t necessary to keep us safe.

David Kang, a North Korea expert and professor of international relations at the University of Southern California, argues that – contrary to some alarmist claims –  the North Korean regime isn’t “crazy,” but is in fact very predictable.

“There are exactly zero examples of a time North Korea caved in to pressure,” he wrote in The Washington Post. “North Korea won’t attack first,” he continued, “because to do so would be regime suicide. But it will fight back if attacked.”

Moreover, should the U.S. launch a war on the Korean Peninsula, the cost to the troops would be astronomically high.

As The New York Times reported: “Roughly 10,000 Americans could be wounded” or killed in combat “in the opening days alone.”

Army Chief of Staff Gen. Mark A. Milley added: “The brutality of this will be beyond the experience of any living soldier.”

It is important to recognize what should be the core objective of U.S. policy on North Korea: to use the most efficient and effective means possible to ensure the North never uses its nuclear weapons.

While a war might eventually eliminate the North Korean military threat, the cost in lives of doing so could be measured in the millions.

Nuclear weapons might be used against American citizens, and egregious damage would be done to the Asian economy, which would have a direct and negative effect on the United States.

Such casualties need never be suffered, however. There are far superior ways to ensure America’s core interests are protected short of preventive military strikes leading to war.

“Deterrence has worked for 65 years, and it can continue to do so indefinitely,” Kang explains. Evidence and logic strongly endorse his analysis. President Trump’s diplomatic opening is a move in the right direction and immediately lowers the danger of war.

Much work remains. Kim has worked for many years to reach the stage where he has an operational missile that can reach the U.S. mainland. He will not give up his only domestic deterrence cheaply and will almost certainly make major demands of the U.S.

Talks are a great beginning but reaching the goal of denuclearization will likely take a lot of painful back-and-forth negotiations. Kim must eventually take concrete, verifiable action to prove his intentions. President Trump is not likely to repeat diplomatic mistakes of the past and will require tangible evidence of compliance.

President Trump has been right to resist those advocating the use of military force to solve the North Korean crisis. Time will tell if Kim is sincere in his claim to work towards full denuclearization. But as has been the case for the past 65 years, even during negotiations, deterrence will continue to keep America safe.