WASHINGTON — President Trump again raised the prospect of nuclear war with North Korea on Tuesday night, boasting that he commands a “much bigger” and “more powerful” arsenal of devastating weapons than the outlier government in Asia.
“North Korean Leader Kim Jong Un just stated that the ‘Nuclear Button is on his desk at all times,’” Mr. Trump wrote on Twitter. “Will someone from his depleted and food starved regime please inform him that I too have a Nuclear Button, but it is a much bigger & more powerful one than his, and my Button works!”
Mr. Trump’s combative response to a statement made in recent days by Mr. Kim raised the temperature in the brewing confrontation between the United States and North Korea even as American allies in South Korea were moving to open talks with Pyongyang. The contrast between Mr. Trump’s language and the peace overture by South Korea highlighted the growing rift between two longtime allies.
The president’s saber-rattling tweet shifted the tenor of his response to the South Korean initiative just hours after a milder initial statement. Mr. Trump, who has scorned the prospects of negotiating with North Korea, earlier in the day said the possible talks between the two governments on the peninsula resulted from sanctions imposed by the United States and the international community. “Perhaps that is good news, perhaps not – we will see!” he wrote Tuesday morning.
Why Mr. Trump hardened his message later the same day was not immediately clear. But he has not hesitated to match North Korea’s incendiary language even while other American presidents resisted such back-and-forth taunting out of concern that it was unwise and unnecessarily rewarding the hermit nation.
Last summer, Mr. Trump vowed to rain down “fire and fury” on North Korea if it posed a threat to the United States. Last fall, he went before the United Nations General Assembly to warn that he would “totally destroy North Korea” if the United States were forced to defend itself or its allies.
Earlier Tuesday, South Korea proposed holding talks with North Korea next week in Panmunjom, a village straddling the border between the two hostile countries. If North Korea agrees, it would be the first official dialogue between the Koreas in two years in what leaders in Seoul hope could dampen the talk of war that has consumed the past few months.
North Korea has made significant strides in the past year in developing intercontinental ballistic missiles that could eventually deliver nuclear warheads to targets as distant as the United States. More than two decades of efforts by the United States and other major powers have failed to thwart North Korea from building a nuclear arsenal in defiance of international law.
Mr. Trump has emphasized a more militant line, arguing that his predecessors were too soft in responding to the threat. He has ratcheted up American sanctions and lobbied the United Nations to increase punitive measures, as well. While at various points in the past he has suggested that he would be open to negotiations, he has more often emphasized lately that he did not believe talks would lead to a fruitful outcome. On more than one occasion when his secretary of state, Rex W. Tillerson, publicly broached the possibility, Mr. Trump pulled him back, declaring, at one point, that talks would be a waste of time.
By any measure, Mr. Trump is correct that the United States has a far more powerful nuclear arsenal than North Korea, but even so, Pyongyang could wreak widespread devastation. Even a conventional war could result in hundreds of thousands of casualties on the Korean Peninsula, according to national security analysts, which is one reason South Korea’s president, Moon Jae-in, is more eager for dialogue than Mr. Trump is indicating he would be.
Many security experts have said there is no reasonable military option for restraining North Korea that would not involve unacceptable loss of life, but Mr. Trump and his national security adviser, Lt. Gen. H. R. McMaster, have argued otherwise.
Whether intended or not, the diverging messages between Mr. Trump and Mr. Moon could create a good-cop, bad-cop scenario in which the South Koreans use the specter of a militant United States as leverage to win concessions from North Korea.
Mr. Kim has sent conflicting messages all by himself. In his New Year’s Day speech that provoked Mr. Trump’s tweet, Mr. Kim both floated the idea of talks and boasted of his nuclear capacity. “It’s not a mere threat but a reality that I have a nuclear button on the desk in my office,” he said. “All of the mainland United States is within the range of our nuclear strike.”
Whether that was mere bluster or not was not clear. North Korea has tested an intercontinental ballistic missile with enough range to reach the East Coast of the United States, but it has not yet shown that it has developed the capacity to deliver a nuclear warhead that could survive the rigors of re-entry through the atmosphere or accurately hit targets at such a long range. But Mr. Kim has made clear that he has made progress in recent months, raising fears in Asia and the United States.