President Trump's refusal to specify when or how he might use military force against North Koreans has emerged as a strategy unto itself amid rising tensions over Pyongyang's continued missile testing and drive toward nuclearization.
The White House faces mounting pressure to set conditions and limits for prospective intervention in North Korea. But officials have avoided tipping their hand as to how the administration will proceed, instead touting Trump's unpredictability as a deterrent for North Korean leader Kim Jong Un to weigh carefully.
"I think unpredictability may have some potential benefits in dealing with North Korea, but there are also risks," said Scott Snyder, a senior fellow for Korea studies and director of the U.S.-Korea policy program at the Council on Foreign Relations.
"So far, I think that what we see is that unpredictability can have the effect of at least inducing a temporary pause," Snyder said. "It can cause North Korea to revisit prior assumptions and to kind of rethink the situation, but it's unclear yet whether that's going to have a sufficient effect to actually bring this to a good conclusion."
Steven Weber, an expert on North Korea and political science professor at the University of California-Berkeley, said Trump's unpredictability likely stems from the fact that his administration does not yet have a clear strategic vision for North Korea.
"I think probably the more realistic thing is that Donald Trump really doesn't know what he's going to do. He knows he doesn't want a war on the Korean Peninsula, but he also knows he doesn't want North Korea to have an arsenal of ballistic weapons," Weber said. "And both sides are sort of in that situation where they know what they don't want, but they don't know what they do want."
The White House's use of unpredictability has not worked as a successful deterrent in the past, Weber argued.
"If Kim Jong Un thinks Donald Trump is a crazy guy and might just start a war over a nuclear test, then that deters him from doing it? I think the evidence of that kind of strategy working is ... zero," Weber said.
He cited as an example the efforts then-national security adviser Henry Kissinger made in 1972 to convince the Soviet Union that Richard Nixon was so "unstable" that he might "do something crazy" if the Soviets defied America's will.
"I don't think national leaders calculate that way," Weber said.
While Trump hinted this week that he would be willing to intervene in North Korea to prevent it from acquiring nuclear weapons that could reach the U.S., he said the administration would prefer a route that avoids war.
"Now I'm put in a position where he actually has nuclear and we're going to have to do something about it," Trump said on Tuesday. "Hopefully he wants peace and we want peace and that's going to be the end determination, but we're going to see what happens."
Harry Kazianis, director of defense studies at the Center for the National Interest, said Trump has options — including secondary sanctions that target any entity outside North Korea that provides materials or support for Pyongyang's nuclear program — that could prevent regional tensions from boiling over into a military conflict.
"I think the Trump administration is looking for ways to basically try to deescalate the situation," Kazianis said.
While Trump has sought to maintain a level of ambiguity with his rhetoric on North Korea, Kazianis said Kim likely understands which provocations would prompt a military reprisal from the U.S., and which wouldn't.
"I don't think it's as ambiguous as one would imagine," he said. "If they hit South Korea, if they hit Japan, if they hit a U.S. base, or they somehow hit the U.S. homeland, that is the only way I could see the us hitting the North Koreans."
On the other hand, Kazianis noted, Kim likely recognizes that continued nuclear and ballistic missile tests are unlikely to draw a direct military response from the U.S.
"For them, that's not actually escalatory; they're going to have to continue testing their missiles if they're going to get to intercontinental ballistic missiles," Kazianis said. "If they eventually want to make a warhead and put it on a missile, they're going to have to continue testing it."
With temperatures in the region running unusually high, Vice President Mike Pence has already issued vague warnings to North Korea during stops in South Korea and Japan this week as he tours Asia-Pacific allies on a whirlwind trip aimed at calming nerves.
Speaking in Tokyo on Tuesday, Pence prioritized a non-military approach to denuclearizing North Korea, but adhered to the administration's practice of keeping the military option open.
"The United States will continue to work with Japan, our allies across the region, and China to bring economic and diplomatic pressure to bear until North Korea abandons its nuclear and ballistic missile programs," Pence said. "But all options are on the table."
Weber, the University of California-Berkeley professor, said "the simplest interpretation of the change in rhetoric" from U.S. officials when it comes to North Korea is that the administration is hoping to "put pressure on China" to play a leading role in containing its aggressive neighbor.
The White House has frequently pointed to Trump's successful discussions with Chinese President Xi Jinping as evidence that the U.S. has made progress toward its goal of bringing China off the sidelines. And Trump was even willing to take a political hit at home to achieve that goal: the president backed off his campaign promise to label China a currency manipulator last week, citing the importance of North Korea talks.
Trump has wielded unpredictability as a weapon in Syria, where he surprised Washington by launching a missile strike on the Assad regime earlier this month in retaliation for its chemical weapons use, and in Afghanistan, where his Pentagon sent an unmistakable message to would-be adversaries by dropping the most powerful bomb in conventional use on an Islamic State encampment last week. But there is skepticism about how successful similar strategies will be against North Korea.
"I think the decisions are made with the information at hand, which is that nobody wants war on the peninsula," Weber said. "The notion that Donald Trump is unpredictable — does the leadership in Pyongyang really believe that Donald Trump is so unpredictable that he would make the decision to start a war that he doesn't want?"
One such move already seems to have backfired on Trump.
The Trump administration said it sent a carrier strike group to waters just off the Korean Peninsula on April 8, a move officials characterized at the time as a show of force intended to underscore the concerns Trump raised during his introductory meeting with Xi days earlier. Coming shortly after the White House signaled that North Korea's successive weapons tests had exhausted U.S. "strategic patience," the movement of the USS Carl Vinson strike group into range of Korea was viewed as a dramatic escalation.
However, the Pentagon admitted Tuesday that a miscommunication led the White House to promote an incorrect timeline for the strike group's arrival in the region, which has not yet occurred. That revelation raised new questions about the message Trump hopes to send to Pyongyang given his reluctance to elaborate on the options under consideration.
"He holds his cards close to the vest, and you're not going to see him telegraphing how he's going to respond to any military or other situation going forward," White House press secretary Sean Spicer said of the president on Monday.
Trump himself weighed in Tuesday on the "very, very tricky situation," and told a local news outlet in Wisconsin that part of the problem stems from his inability to know what Kim Jong Un is thinking.
"Look, you always have to be concerned," Trump told CNN affiliate WTMJ. "You don't know exactly who you're dealing with."