SEOUL, SOUTH KOREA - Donald Trump approached North Korea with threats of "fire and fury," followed by made-for-television summits with its leader, Kim Jong Un.
For Barack Obama, it was "strategic patience," which tried to use steady economic and military pressure to convince Pyongyang to return to talks.
Now President Joe Biden is attempting what U.S. officials describe as a middle ground between his predecessors' approaches, which they acknowledge failed to achieve U.S. objectives.
White House officials late last week unveiled the broad outlines of Biden's North Korea strategy, following a months long internal review.
Under Biden's plan, the U.S. will maintain pressure on North Korea to give up its nuclear weapons but will also pursue talks - and perhaps even intermediate deals - to help advance that goal.
Depending on how the strategy plays out, it could represent a significant change in how the U.S. handles one of its most urgent foreign policy challenges.
A new approach?
Most U.S. administrations have shied away from a phased approach to denuclearization, fearing North Korea will cheat on any interim deal and thus gain valuable time to build up its nuclear program.
But the Biden administration appears to be leaving the door open for improved relations, even short of a grand bargain with North Korea.
White House Press Secretary Jen Psaki said Friday the U.S. will pursue "a calibrated, practical approach" that will explore "options for diplomacy."
Speaking to The Washington Post, a U.S. official went further, saying the U.S. may offer North Korea unspecified "relief" in exchange for "particular steps," even while retaining the "ultimate goal of denuclearization."
"If the Trump administration was everything for everything, Obama was nothing for nothing ... this is something in the middle," the U.S. official told the paper.
As of now, Biden's policy could be dubbed a "something for something" approach, quipped John Delury, a professor at Seoul's Yonsei University.
What's the deal?
Though it is not clear what "something" each side would offer, there are many options.
During Trump's outreach to Kim, U.S. officials reportedly considered declaring a formal end to the Korean War, a symbolic step that would signal a less pressure-focused approach. Both sides also considered establishing liaison offices in each other's countries.
U.S. officials could also try to formalize North Korea's pause on nuclear and long-range missile tests. Or they could attempt to work out a more extensive interim deal to limit North Korea's weapons development.
North Korea is estimated to have enough fissile material for dozens of nuclear weapons, but analysts say Pyongyang still needs to do more tests before it can reach the U.S. with a nuclear-tipped missile.
North Korea not interested
For now, it doesn't appear North Korea wants to engage in negotiations at all.
Since the coronavirus pandemic, North Korea has undertaken one of the world's most extreme lockdowns, even sealing its borders with China, its economic lifeline. North Korea says there are no coronavirus cases in the country, but these claims are widely disputed.
While little is known about North Korea's pandemic situation, it plays a major role in when Pyongyang will choose to engage the U.S., says Park Won-gon, a professor at Ewha University in Seoul.
"We all know that North Korea simply does not have any means to deal with this pandemic," he says, noting the issue is a major security threat for Kim's rule.
On Sunday, a senior North Korean diplomat lashed out at Biden, calling Washington's efforts at diplomacy a disguise for its "hostile policy."
The North Korean diplomat also expressed frustration that the U.S. and South Korea recently conducted joint military drills. In a separate statement, a North Korean official took issue with the Biden administration's recent criticism of Pyongyang's human rights record.
North Korea has boycotted talks with the U.S. since 2019. At a summit in February of that year, Trump rejected an offer in which North Korea would dismantle a key nuclear complex in exchange for the U.S. lifting most sanctions.
Trump preferred a more wide-ranging deal in which the U.S. would lift all sanctions in exchange for North Korea completely dismantling its nuclear program.
A growing number of former U.S. officials and other Korea watchers have criticized that all-or-nothing approach, saying it may be necessary to focus on reducing rather than eliminating the threat.
While the Biden administration is signaling "step-by-step diplomatic engagement," much depends on how North Korea responds in the coming months, says Leif-Eric Easley, another professor at Ewha University.
"If Pyongyang agrees to working-level talks, the starting point of negotiations would be a freeze of North Korean testing and development of nuclear capabilities and delivery systems," Easley says. "If, on the other hand, Kim shuns diplomacy and opts for provocative tests, Washington will likely expand sanctions enforcement and military exercises with allies."
More challenges coming?
North Korea last month conducted a short-range missile test, its first ballistic missile launch in about a year. Pyongyang has hinted bigger tests may be coming.
It is not clear how Biden would respond to such launches. Biden criticized last month's test as a violation of United Nations Security Council resolutions and warned of more responses should North Korea escalate.
"The Biden administration has been clear that the era of love letters and theatrical summits as a starting point for diplomacy is over," says Jean Lee, director of the Korea Program at The Wilson Center in Washington D.C.
"Hopefully, the administration will build on the diplomatic progress made over the past four years instead of jettisoning everything from the Trump years - but come up with a long-term strategy that takes all stakeholders in the region into account," she adds.
Will Biden be proactive?
But some in the region, especially South Korea, fear North Korea will not be a priority for Biden, who is focused on issues such as the coronavirus pandemic, economy, and reviving the Iran nuclear deal.
"It's a negative agenda item for Biden because there's low return and high risk," says Kim Joon-hyung, chancellor of the Korea National Diplomatic Academy, which trains South Korean diplomats.
In Kim's view, the Biden administration should be proactive and meet the North Koreans as soon as possible. He also recommends that the U.S. be open to compromise, noting that North Korea's nuclear program is growing every year.
"If the U.S. wants all or nothing," he says, "then they can always get nothing."