- President Donald Trump and North Korean leader Kim Jong Un are still on polite terms, but the US and Pyongyang have recently floated the idea of resuming hostilities.
- Trump reportedly made a verbal promise to Kim that he'd end the Korean war, but hasn't come through.
- North Korea said it could resume missile testing if the US doesn't move on a peace process.
- Trump and Secretary of Defense Jim Mattis said the US could go back to military drills, this time bigger than ever before.
- It seems that shaky, unwritten understandings between Kim and Trump are all that's keeping the US and North Korea from their fiercest-ever confrontation.
President Donald Trump forged a summer of diplomatic progress with North Korea after walking back from the brink of nuclear war in 2017 — but a recent return to threats shows just how dangerous the situation still is.
Trump left the Singapore summit with praise for North Korean leader Kim Jong Un, heralding a new era of peace and prosperity for the country, as well as the end of the nuclear threat from Pyongyang.
But Pyongyang has kept its nukes, and appears in no hurry to discard them. Now US patience has worn thin.
Trump promised Kim that the US would officially end the Korean War, which has technically been running since June 1950, as part of the peace and denuclearization process, Vox reported on Wednesday.
The US has maintained that a peace treaty can only come after steps towards denuclearization, but North Korea pushes for the reverse.
Trump canceled Secretary of State Mike Pompeo's trip to North Korea after Pyongyang sent a "belligerent" letter to the US warning that they may resume "nuclear and missile activities" if progress towards a peace treaty isn't made.
Secretary of Defense Jim Mattis recently said that the US and South Korea could resume military exercises, a major irritant in the relationship with Pyongyang and a concession Trump personally made to Kim in Singapore.
Trump on Wednesday ratcheted up that prospect, saying that if the US does restart military drills, they "will be far bigger than ever before."
Both sides prepped for massive escalation
But Trump's last full round of military drills in 2017 already pushed the envelope for how big a drill could get without spooking North Korea into a first strike.
In April 2017, the US had three aircraft carriers off North Korea's coast and stood at the brink of full-on war.
As North Korea's missiles become longer range, and its nuclear weapons larger in destructive power, the only tests left for Pyongyang to run would likely involve massive, possibly intolerable escalations.
For example, before ending testing in 2018, North Korea had standing threats to fire missiles at US forces in Guam and detonate an armed nuclear warhead over the Pacific.
After the Singapore summit, experts dismissed Trump and Kim's joint statement as empty words each side had often said before without a result.
But months later, time and reporting have revealed that the most important aspects of the deal took place under-the-table and verbally, with Trump saying he'd declare an end to the war and stop military drills.
For now, Trump said he sees no need to continue military drills with South Korea or put military pressure back on Kim, whom he calls a friend.
North Korea has broken every agreement it's ever made with the US, and has often done so with high profile launches.
Trump often touts North Korea diplomacy as a major win of his presidency, but how he would respond if Kim betrayed the spirit of their friendship with an embarrassing missile launch remains an open question, with potentially dangerous answers.
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