Pyongyang is ratcheting up its diplomatic warnings and conducting long-range static rocket-engine tests to pressure Washington to weaken its negotiating position. For months, the regime has threatened dire consequences at year’s end if the U.S. does not abandon its demand for North Korean denuclearization.

President Donald Trump expressed confidence that Kim Jong-un will not initiate provocative actions, but the U.S. has recently appealed to the United Nations for a strong response should Pyongyang proceed with a nuclear test or an intercontinental ballistic missile (ICBM) test.

There are rising concerns that Washington could either return to threats of a preventive attack or acquiesce to a flawed agreement. Both options would be a mistake. Instead, Washington must implement a comprehensive strategy of military deterrence, containment, pressure, law enforcement, and confrontation of North Korean human rights violations.

North Korean Warnings. In April 2019, Kim Jong-un declared that he would wait only until the end of the year for the U.S. to comply with his negotiating demands, at which point the prospect for settling the issues will be “gloomy and very dangerous.”REF North Korean officials have recently become more strident in their invective and are now willing to directly criticize and insult President Trump.REF

North Korea rejects further working-level diplomatic meetings, as well as another “useless” summit with President Trump. Pyongyang also does not believe in “gift[ing] the U.S. president something he can boast of” as the U.S. “pretends it has made progress in settling the issue of the Korean Peninsula.” In early December, North Korean Ambassador to the United Nations Kim Song declared that “denuclearization is already gone out of the negotiating table,” while Vice Foreign Minister Ri Thae-song warned that it is “entirely up to the U.S. what Christmas gift it will select to get.”REF

Concurrent with its increasingly harsh language, North Korea conducted two rocket-engine tests at the reactivated Sohae Satellite Launching Ground. The regime’s proclamation that the second event would “further bolster up [its] reliable nuclear deterrent,” and that the tests aid the “development of another strategic weapon,” suggests that an ICBM stage was tested. The Trump Administration previously cited the rocket test facility’s dismantlement as a sign of progress toward North Korean denuclearization.

North Korea announced it would hold a Korea Workers’ Party plenum in the last 10 days of December due to “changed internal and external situations.” Convening a second plenum in one year is highly unusual and could portend Kim Jong-un reversing his April 2019 plenum pledge to discontinue nuclear and ICBM tests and dismantle North Korea’s nuclear test site.

Mixed U.S. Response. President Trump downplayed the potential for provocative North Korean behavior since Kim “does not want to void his special relationship with the President of the United States or interfere with the U.S. presidential election in November.”REF However, in a sign that Washington may be considering stronger actions, U.S. Ambassador to the U.N. Kelly Craft voiced strong concern about possible North Korean firings of ICBMs—which “are designed to attack the continental United States with nuclear weapons,” using language reminiscent of the 2017 crisis. In 2017, the Trump Administration deemed Pyongyang crossing the ICBM threshold to be “intolerable” and justification for a U.S. preventive military attack on North Korea.REF Craft also offered Pyongyang a way out of the crisis by emphasizing that the U.S. is “prepared to be flexible” in its negotiations with Pyongyang.

Brinksmanship as Negotiating Tactic. North Korea’s increasingly strident statements, rocket-engine tests, and 26 short-range missile launches in 2019—more violations of U.N. resolutions than in any previous year—reflect its willingness to raise tensions.

Pyongyang may move incrementally up the escalation ladder to garner concessions before returning to diplomatic talks. Options include medium-range and intermediate-range missile launches and a space-launch vehicle before crossing President Trump’s red line of nuclear and ICBM tests. The regime could also restore its mothballed nuclear test site, unveil a new missile system or submarine, or conduct low-level military provocations in the West Sea near South Korea.

North Korea has closed, though not yet locked, the door on negotiations. Historically, Pyongyang has moved slowly to implement its threats, seeking to gain negotiating leverage or objectives. But, the regime could maximize its leverage by moving immediately to a long-range missile or nuclear test to confront Washington with a high-stakes crisis.

Kim Jong-un may feel that he has the upper hand when confronting the United States. North Korean officials have repeatedly referenced the 2020 U.S. election, believing that threats of resuming nuclear and ICBM tests would hang as the sword of Damocles over President Trump’s head and would hence induce additional concessions.

How the U.S. Should Respond. The Trump Administration must chart a course between the twin flaws of over-reacting and under-reacting to North Korea’s defiance of U.N. resolutions. While the U.S. should remain vigilant and resolute against any North Korean attack, it should not return to the “fire and fury” rhetoric of threatening a preventive strike.

The U.S. should not initiate an attack on North Korea for crossing a technological threshold, since that would risk precipitating a full-scale war with a nuclear nation, leading to massive casualties. The more prudent course of action is to reserve a pre-emptive attack for a situation in which the Intelligence Community has strong evidence of imminent strategic nuclear attack on the U.S. or its allies.REF

The Trump Administration should also resist entreaties to lower the negotiating bar to achieve progress. President Trump should reject calls for relaxing sanctions in return for only a partial, flawed agreement that does not include a clearly defined endpoint of North Korean abandonment of its nuclear and missile production facilities and arsenal, as well as rigorous verification protocols.

The U.S. should end its policy of repeated concessions to North Korea. The Administration’s “maximum pressure” policy has never been maximum. Since the Singapore summit, President Trump has constrained the enforcement of U.S. laws, weakened allied deterrence capability, embraced a purveyor of crimes against humanity, and overlooked numerous North Korean violations of U.N. resolutions.

The Trump Administration should ratchet up pressure on North Korea and foreign enablers of its prohibited nuclear and missile programs. Washington should sanction the 300 North Korean entities referenced by President Trump in June 2018, penalize Chinese financial institutions engaged in money laundering and other crimes, impose secondary sanctions against entities aiding North Korean evasion of sanctions, return to the previous level of military exercises, repair strained relations with its Asian allies, and uphold human rights principles.

Pyongyang is not reticent to create crises to serve its purposes. While Washington should remain open to negotiations, it must respond sensibly by not giving in to extremist recommendations that could lead to war or capitulation. Prudent application of pressure with diplomatic outreach, while maintaining a strong deterrence and defense posture, is a more effective strategy for achieving U.S. objectives.

Bruce Klingner is a Senior Research Fellow in the Asian Studies Center, of the Kathryn and Shelby Cullom Davis Institute for National Security and Foreign Policy, at The Heritage Foundation.