Moon Jae-in’s election ended the leadership vacuum caused by the first-ever impeachment of a sitting president and restored liberal government rule after a nine-year absence. The overwhelming victory the former human rights lawyer clinched in his second bid is a crowning moment for him. 

But the new president faces such urgent, formidable challenges that there is no time for celebration.

The first of multiple challenges is to restore national leadership, which was severely damaged by the scandal involving former President Park Geun-hye and her confidante Choi Soon-sil, leading to the subsequent removal of Park from office. 

The political crisis caused by the scandal and impeachment was made worse by the confrontation between the anti-Park and pro-Park groups, which further widened already deep regional and ideological divides in the country.

Moon’s most urgent job is to address the divide, which he and other presidential candidates had exploited to garner voter support. Most of all, he needs to reach out to his former opponents, especially hard-line conservatives. It was hopeful for Moon to speak -- soon after exit polls indicated his victory -- not only about reform but also integration. 

Another big challenge is that, having been elected in a by-election, Moon assumes office without the traditional two-month transition period. The president is to take office Wednesday morning, which would mean everything has to be rushed -- from settling in the office to appointing senior administration officials and setting top policy priorities.

Moreover, Moon launches a government lacking control of the National Assembly, where his Democratic Party of Korea -- the biggest group in parliament -- has only 120 seats, far short of the 151 needed to secure a simple majority.

These and other challenges call upon him to faithfully keep the promise of “cooperative governance” for which he should form a Cabinet totally different from past administrations.

It would be good if the new Cabinet includes people from a pool so broad that it could be called a coalition government. If not, the president, as he promised during the campaign, should include enough people beyond his own partisan, political and regional influence.  

The president might face backlash from loyal supporters for bringing in people from other camps, but that would be outweighed by the benefits of sharing power with opposition figures.

A leader cannot win everything. We already witnessed what happened when the most recent leaders -- Roh Moo-hyun, Lee Myung-bak and Park Geun-hye -- failed to break free of a “winner-takes-all” framework in the early stage of their presidencies.

The new chief executive should be humble, not least because he is taking office under an extraordinary situation.

One piece of advice that Moon needs to keep in mind is that the reorganization of ministries and other key government offices should be minimized.

Most government reorganization initiatives of past presidents -- even with enough preparation during the transition period -- ended in failure.

As a leader who came to power amid an unprecedented political crisis, the president should not direct energy to delving into the past or settling old scores.

There are many daunting challenges for the president to tackle: tension over North Korea’s nuclear and missile provocations and the economy, to name but a couple. Sights need to be set on the present and future, not on the past.

For their part, the opposition and the media, as well as the other four major candidates who lost to Moon, need to be patient in dealing with the new president and administration. If no serious blunders are made, the president should be given the time necessary to settle into the job.

The nation and its citizens have suffered too much over the past months. Moon’s election should end the suffering and mark a new start, for all Koreans. 

And the entire nation -- including those who did not vote for him -- should stand behind the president so that he can take the country in the right direction.