Without the US wielding a stick, would Kim Jong Un have grabbed a carrot?

The world watched in awe the stunning events in Panmunjom in the Demilitarized Zone separating North and South Korea: a jovial Kim Jong Un and beaming Moon Jae-in embracing, surrounded by glorious Olympics-style Korean pageantry.

The historic meeting between the North Korean leader and South Korea’s president has media commentators and academic/think tank experts struggling to determine how much credit — or how little — President Donald Trump deserves for the amazing developments on the Korean Peninsula.

{mosads}Just months ago, many urgently warned that the president’s “fire and fury” rhetoric against the Kim regime, mirroring the chilling threats that have regularly emanated from Pyongyang, would recklessly move the world toward nuclear war — even World War III, if China got involved.

Now, these critics grudgingly acknowledge that Trump’s tough talk against North Korea and China, its protector and enabler, may have motivated the two communist regimes to get serious about halting, if not dismantling, Pyongyang’s nuclear and missile programs.

Unaccustomed as some are to finding anything positive to say about Trump administration policies, they dilute their limited praise by asserting that it actually was President Moon’s ardent pursuit of reconciliation with North Korea that has paid off. According to this narrative, Kim finally has a positive, welcoming message to which he can respond in kind, rather than Trump’s insults and threats, which only provoke more vituperation from Pyongyang.

That much-repeated rationale ignores some history. For decades, prior South Korean leaders also offered numerous olive branches to Kim regimes — most notably Kim Dae-jung’s “Sunshine Policy” — only to be disappointed by North Korean rejection, deception and continued nuclearization.

As should have been evident all along, not just in hindsight, the missing ingredient in past overtures from “good-cop” South Koreans was the credible threat of force from an American “bad cop” — offering a stick to go along with the carrot. In fact, it was only when prior administrations seemed about to adopt that tougher approach that Pyongyang showed interest in serious negotiations. But the lack of U.S. follow-through took the pressure off and the North Koreans returned to their nuclear and missile paths.

This time around, Pyongyang — and Beijing — saw Trump’s statements, as a candidate and then as president, and sensed that something was different. The consistent warnings from him and his national security team, whether couched in softer or harsher terms, conveyed a message that Washington’s strategic patience was wearing thin and that it was only a question of when, not whether, U.S. military action would come into play.

Increasingly punishing sanctions began to take their toll on both economies, and hints of “bloody nose” strikes were ominous enough. But what almost certainly convinced Pyongyang and Beijing that the Trump administration was playing for keeps was the president’s unprecedented intense focus on the human rights situation in North Korea.

During the campaign and since his election, Trump had made several seemingly off-the-cuff references in tweets and public remarks to the horrible treatment of the North Korean people under the Kim regime. Then, in his address to the United Nations General Assembly in September, his speech before South Korea’s National Assembly in November, and his State of the Union address in January, the president laid out a graphically detailed indictment of North Korea’s atrocities that human rights experts have concluded amount to crimes against humanity. The United Nations has voted to refer the case to the International Criminal Court for prosecution. While China and Russia have blocked the move so far, it greatly enhances Washington’s leverage over Pyongyang.

Trump punctuated the rhetoric in a dramatic meeting in the Oval Office with North Korean victims who described in emotional personal terms both their shocking experiences under the Kim dynasty and their deep appreciation for the sympathetic hearing afforded them by this American president.

All this presidential attention to the human rights situation in North Korea, in effect, lays out the case — quite apart from the nuclear issue — either for tectonic change in the Kim regime’s behavior or a change of the regime itself.

That may well explain the major shift in attitude by Pyongyang and Beijing and the new smiling face Kim is presenting to the world. If he and his Chinese benefactor remain convinced that the Trump administration intends to see significant changes in North Korea, they will strive to extract a U.S. commitment not to seek regime change. That provides major leverage to the president on both the denuclearization and human rights fronts.

After all the critical commentary from American and European observers that Trump cares less about human rights than any president in recent history, the emergence of humanitarian concerns as a motivating factor, and its strengthening of the president’s overall negotiating posture, is striking — a supreme and surprising irony.

Joseph Bosco served as China country director for the Secretary of Defense from 2005 to 2006 and as Asia-Pacific director of humanitarian assistance and disaster relief from 2009 to 2010.  He previously taught a graduate seminar in the Asian Studies Program at Georgetown’s School of Foreign Service. He is a nonresident fellow at the Institute for Corean-American Studies and the Institute for Taiwan-American Studies, and has held nonresident appointments in the Asia-Pacific program at the Atlantic Council and the Southeast Asia program at the Center for Strategic and International Studies.