“My guess is that those will include a significant amount of secondary sanctions on Chinese companies dealing with the North Koreans, especially if the meeting between Presidents Trump and Xi Jinping in April does not result in China taking a significantly different approach.”

During his visit to Seoul last month, incumbent Secretary of State Rex Tillerson declared strategic patience over, saying all options including military action are on the table in Washington’s ongoing policy overhaul.

Yet Trump’s team has so far shown a “strong tenacity” to follow in the footsteps of Obama, who had come to fully recognize the gravity of North Korea’s nuclear and missile problem especially in his last year, and thus worked to present a “full-fledged and fleshed-out approach” to his successor, Straub said.

Tillerson’s remarks on the military option rather represents a “standard language” used by virtually all past US administrations, but it has “never been planned or intended,” he noted, indicating risks of escalation and its potential impact on tens of thousands of US citizens and soldiers and their families in the South.

“Of course one can never be 100 percent sure about President Trump, but the consensus among people in the US government is that we have to put enough pressure on North Korea so that their leaders understand we’re not going to give in, and accept them as a nuclear weapons state ... until the current leadership is ready to have serious negotiations, which we’re willing to do,” he said.

“Or there is so much psychological pressure within the leadership that some change happens within the government itself. That’s not a regime change policy, but if the pressures are continuing, definitively it could result in a regime change.”

In recent weeks, speculation has been growing that the Kim Jong-un regime may be preparing for its sixth nuclear test or intercontinental ballistic missile launch in celebration of upcoming major holidays including for the birth of late founder Kim Il-sung, a ruling party assembly and the anniversary of the creation of its military.

But neither test is likely to be a game changer for either Washington or Beijing, though a potential test could have a personal impact on Trump, who in the eyes of Straub has not “significantly involved himself yet” in North Korea policy discussions.

“Now the question becomes, after he’s having said that North Korea is not going to develop an ICBM and so for publicly taking a strong negative position, what will be his personal and emotional action to North Koreans telling him to go take a flying leap?” Straub said, referring to Trump’s tweets on Pyongyang.

“I strongly doubt that it would fundamentally change the Chinese thinking. But if it makes Trump very upset and it makes the Chinese even unhappier, it’s possible it could have some significant impact on the future course of US policy and also Chinese policy.”

Until his 2006 retirement, Straub served in the diplomatic service for 30 years and was deeply involved in Northeast Asia affairs. He was at the State Department’s Korea and Japan Desks and spent nearly eight years at the US Embassy in Seoul.

For Straub, his 37-year ties with Korea were the concoction of fate and coincidence.

Korea was a “concept” to a boy whose father, a Korean War veteran, was “constantly talking” about the country. Then a chance that came to a 24-year-old young officer in 1978 defined his entire career -- he was posted to Seoul the following year amid a political and socioeconomic vortex, and has worked almost solely on Korea and Japan relations ever since.

“By the early 1990s, I’d ruined my career because as a diplomat, you’re supposed to spend two or three years in one place and move somewhere,” Straub quipped.

“But that was OK, because I found it fascinating to try to understand cultural differences, and both countries were rewarding for an American who worked in the embassy. ... (Korea) was a fascinating place, politically, economically and culturally.”

While working as associate director at Stanford University’s Asia-Pacific Research Center, he authored two books on the two Koreas and their relations with the US. The Korean edition of his 2015 book, “Anti-Americanism in Democratizing South Korea,” in which he examines anti-American sentiment based on his first-hand observations and extensive case studies, was published here last month.

By Shin Hyon-hee (heeshin@heraldcorp.com)