Last week’s first in-person summit between South Korean President Moon Jae-in and US President Joe Biden served to put the two countries’ alliance back on track. Their agreement on a broad range of issues is expected to help expand the scope and depth of the seven-decade-long alliance beyond bridging differences that came to the fore under the presidency of Biden’s predecessor Donald Trump.

What made this possible were efforts by the two leaders to come closer to each other’s requests, based on the need to upgrade cooperation between the allies to a higher dimension amid changing regional and global conditions.

At their summit in Washington on Friday, Biden reaffirmed his willingness to engage diplomatically with North Korea, backing Moon’s push to revive his stalled Korean Peninsula peace process.

A joint statement issued after the summit made clear the Biden administration’s commitment to previous inter-Korean and US-North Korea accords, including the Panmunjom Declaration and Singapore Joint Statement that Moon and Trump signed with the recalcitrant regime’s dictator Kim Jong-un in 2018, respectively.

Holding a press conference with Moon following their talks, Biden said he might meet with Kim on the condition that Kim makes a serious commitment to discuss giving up his state’s nuclear arsenal, which would have to be verified in pre-meeting negotiations.

In a show of the robustness of the alliance, Moon and Biden agreed to terminate all US guidelines that have restricted South Korea’s missile development since 1979.

They also agreed on the need for the two countries to pursue a global COVID-19 vaccine partnership, broaden cooperation in the nuclear energy sector and work together to achieve their shared goal of net zero greenhouse gas emissions by 2050.

In what could be seen as quid pro quo for Washington’s more positive response to Seoul’s agenda, Moon agreed to address two sensitive issues his government had shunned in the joint statement.

The document said the two countries agreed to work together to improve the human rights situation in the North and opposed all activities that undermine, destabilize or threaten the rules-based international order in an indirect reference to China’s increasing assertiveness. Notably, Moon and Biden emphasized the importance of preserving peace and stability in the Taiwan Strait as well as maintaining freedom of navigation in the South China Sea and beyond.

They agreed on the “fundamental importance” of trilateral cooperation involving Japan in dealing with North Korea, protecting regional prosperity and bolstering the rules-based global order.

It has yet to be seen whether the Moon administration is ready to depart from its blind pursuit of inter-Korean reconciliation and its insistence on maintaining an equal distance from Washington and Beijing. But it will be inevitable for South Korea to carry forward its consolidated and expanded alliance with the US to better secure its national interests while adjusting its approaches to the North and China in consideration of changing conditions on the ground.

Moon might well hope to make a breakthrough in stalled inter-Korean ties before he leaves office next year. But he needs to recognize Pyongyang will probably remain unenthusiastic toward an overture from a South Korean leader whose tenure ends not long after.

The Biden administration makes much of South Korea as a strategic partner in its drive to build global supply chains free of possible disruptions in China. In the joint news conference with Moon, Biden hailed major South Korean companies’ plans to invest nearly $40 billion in high-tech fields such as chips, electronic vehicles and batteries in the US.

Seoul has said it will maintain a close security alliance with the US while enhancing economic partnership with China. This position is becoming increasingly unviable. Being excluded from the US-led global supply chains could cripple the Korean economy.

South Korea also needs to be more active toward joining the Quad group, which brings together Australia, India, Japan as well as the US. It will weaken its strategic position if it continues to stay outside the quadrilateral framework, which is set to expand its scope of cooperation from security to other areas in what can be viewed as keeping a rising China in check.