The word “south-south conflict” describes the different — often opposite — positions South Koreans take on North Korea, be of its leader, its security threat or how to achieve reunification.

The conflict escalates when there is a major crisis — like the North’s torpedo attack on the South’s Cheonan corvette in 2010. Some South Koreans still dispute the Seoul government’s finding that the naval ship and 46 of its crew sank after a torpedo attack from a North Korean submarine.

Sometimes opposition lawmakers become sources of unfounded arguments and rumors, which spread quickly on the Internet and social media. For instance, there were rumors that the Cheonan struck a rock and some even raised the possibility of the South Korean Navy or the U.S. perpetrating the attack.

So when military tensions on the border were racing to their highest point in years this past week, many worried that the all-familiar south-south conflict might arise over the latest crisis.

But what we saw was the opposite. There were very few who disputed the Defense Ministry’s announcement that the land mines that maimed two South Korean soldiers in the southern side of the Demilitarized Zone had been planted by the North. Nor was there any loud criticism of the Seoul government’s response to the North’s land mine provocation and the ensuring exchange of artillery fire. 

A big credit for this rare unity in dealing with North Korea could go to the main opposition New Politics Alliance for Democracy and its leader Moon Jae-in.

Moon condemned the North as soon as the Seoul government announced that the mines had been planted by the North. He paid a visit to the wounded soldiers at hospital. 

The day after the North fired artillery shells to intimidate the South’s propaganda broadcasts, Moon visited a frontline town to meet residents staying in a shelter and presided over a meeting of senior party members at the border village of Imjingak.

After the South returned the North’s artillery fire, the NPAD issued a statement condemning the North before the ruling party did. Moon and the opposition party were also very active in the adoption of a parliamentary resolution.

All this is a far departure from the past. Some detractors say the NPAD, a liberal party which often faced criticism for excessively sympathizing with the North, is trying to broaden its support base ahead of the parliamentary elections next year and the 2017 presidential poll, for which Moon is a major potential candidate.

Whether they had political motives or not, the opposition’s clear, consistent position helped the nation rally behind President Park and the military in coping with the threat of an imminent armed conflict with the North.

It is hoped that the opposition — more broadly the political community — upholds such a “national-interest-first” attitude toward other major national agendas too, like the pending labor reform talks and the economy. President Park, who called in lawmakers of the ruling party for a lunch at the Blue House after defusing the crisis, would do well to invite Moon and other NPAD leaders as well.