As gunfire resounds across over the Korean Peninsula, it may well be time to declare the once-chummy bromance between North Korean leader Kim Jong Un and South Korean President Moon Jae-in dead.

On Wednesday, a South Korean warship fired warning shots across the bow of a North Korean merchant vessel that had strayed across the divided peninsula’s maritime border in the Yellow Sea. Ten days prior to that, North Korea had conduced artillery drills, also in the Yellow Sea.

Granted, the South Korean firing was merely shots across the bow. And South Korea’s partly state-owned Yonhap news agency put a fine spin on it, headlining its report, “S. Korea guiding N.K. merchant ship out of its waters.” The North Korean vessel, apparently, was suffering from engine problems, and there were no damage, injuries or return fire reported. In fact, a similar incident had happened the month prior.

But clearly: intrusions and shootings are not amicable incidents. And Pyongyang has been firing regular test barrages of short-range missiles and rockets throughout much of the year.

The artillery drills conducted by North Korea in the waters of the Yellow Sea were more serious. Five days after those drills – suggesting, perhaps, a period of behind-the-scenes discussion – they drew a rare and strong rebuke from a Seoul that has, over the last two years, sought to portray the upside of virtually every inter-Korean interaction.

What made the drills particularly galling for South Korea were their location and timing. They took place in an area, and on the ninth anniversary, of a North Korean artillery strike that killed four South Koreans on the Yellow Sea island of Yeongpyong in 2010.

Moreover, according to North Korean media, the drills – which the South Koreans also insist violate a 2018 military agreement signed by the two capitals – were personally ordered by Kim Jong Un.

That looks like a real kick into the groin of Moon.

The latter, after all, has made inter-Korean rapprochement his flagship policy; appears to have delighted in his three summits with Kim; and has gone all out to be an intermediary between the North Korean leader and Seoul’s most important ally, US President Donald Trump.

ménage à trois that could never work

Despite appearances of fraternity, any bromance between the democratically elected leader of a country with a population that vocally proclaims its rights and a hereditary dictator who leads one of the world’s most repressed societies was always going to be tricky to maintain.

Adding strain to any Kim-Moon relationship was the fact that it was never a one-on-one: It was a ménage à trois. The United States – South Korea’s stern, ever-present and sometimes overbearing guardian – was always going to come between the two.

Precedent-smasher Trump – to his credit – tried to make it a true love triangle, by extending his embrace to Kim. Getting cozy with a North Korean leader was something no POTUS had previously had the chutzpah to do.

But three-way relationships are even more difficult to maintain than bilateral affairs. And making the Kim-Trump dalliance extra sensitive was a deep chasm of distrust dividing Pyongyang and Washington.

Few pundits seriously believed that Kim was truly willing to denuclearize. Trump’s non-negotiable insistence that Kim ditch his hard-won nukes before offering him any concessions made any denuclearization baby steps by Kim doubly problematic. Finally, the inability of both sides to make working levels actually, well, work, doomed the effort.

After all, top-down diplomacy can only do so much: Contact, agenda, procedure, detail and follow-up are important.

Moon falls into arms of Trump – not Kim

The impossibility of maintaining such an improbable love triangle forced Moon to choose a single bedfellow.

Make no mistake: His choice has been Trumpian America, not Kimian North Korea.

Many US-centric pundits fret about the state of Washington’s alliance with Seoul. They fume about Moon’s leftist leanings. They chafe at his eagerness to leap into bed with Kim. And they carp about his endless bashing of Tokyo.

But despite this sniveling and fussing, the on-ground reality is clear. Moon has not dragged Seoul into the Beijing-Moscow-Pyongyang orbit. Quite to the contrary, he has not broken US-led United Nations sanctions – Trump’s “maximum pressure” campaign.

In other words, he has stuck to his alliance with the United States.

That may have been the only pragmatic choice to make, but it can’t have been easy. As a direct result, Moon’s greatest presidential dream remains a dead duck. His endlessly stated hopes for a “Peace Economy” – a broad vision of trade, investment, roads, rails, pipelines and people-to-people contact linking the two Koreas over the Demilitarized Zone – have gone precisely nowhere.

This total lack of momentum has irked Pyongyang, which accuses Seoul of failing to keep its promises. But absent something truly seismic happening in regional or global geopolitics, relations look set to remain exactly where they are for the foreseeable future.

Will Kim aim new kisses at Moon?

No doubt, there will be continued upbeat messaging from Seoul about engagement with North Korea, about the happy moments of the last two years and about the potential of the future. And North Korea may be more reciprocal in 2020.

Pyongyang said in April that it would give Washington until the end of this year to play ball, then would reassess its engagement policy with Trump. That clock is ticking ever faster. It seems unlikely that there will be a third Kim-Trump summit before the end of this year. Even if there is, it seems highly unlikely that there will be any breakthrough, for reasons noted above.

What looks more likely is Pyongyang anxiously watching US domestic political developments in 2020, as Trump battles for re-election. It may carry out minor provocations aimed at South Korea and Japan – artillery and short-range missile tests – but will it risk relations with the US by detonating another nuclear device or testing an intercontinental ballistic missile (ICBM)? Given that these are the only fruits of Trump’s wooing of Kim, quite probably not.

So in 2020, anticipate a quiet year on the North Korean-US front. But with Pyongyang-Washington relations deep-frozen there may be a slight warming of the North’s attitude toward the South.

Any such thaw would be seized upon in Seoul, which delights in any inter-Korean act, however symbolic. But symbolism is no substitute for substance. And the chances of any drastic improvement in inter-Korean relations are low, for reasons that have little to do with the United States and everything to do with the two Koreas.

What dooms inter-Korean love

North Korea is linguistically and culturally close to South Korea. But South Korea’s politics, economy and society are radically different from those of North Korea.

On the individual level, the life experiences, daily lives, habits, value systems and aspirations of South Koreans are closer to Americans’ than they are to North Koreans’. The latter persons, after all, lack such basic rights as freedom of travel, freedom of information, freedom of religion or freedom of speech.

Kim and Moon can paper over these differences with photo ops and shared bonhomie. But deep down, their systems are worlds apart. So while there may be some re-ignition of the Kim-Moon bromance next year, a likelier outcome is stasis.

And post-2020 – regardless of who the next POTUS is – the most likely outcome is a return to the decades-long status quo of confrontation and containment.

Given the high hopes of early 2018 – when Kim came out of the cold and summited with Xi Jinping, Moon and Trump, opening up new realms of sunlit possibility – this is a depressing thought. But amid the mighty risks that hover over the Korean Peninsula it is, at least, a modus vivendi that the Koreas, the United States and the world are well practiced at.