On the surface, the gathering of the leaders of South Korea, China and Japan in Seoul seemed to have achieved their primary goal -- restoring the three-way cooperation that had stalled dues to historical territorial disputes for more than three years.

President Park Geun-hye declared after hosting talks with the Chinese and Japanese leaders Sunday that the three countries have “fully” restored their trilateral cooperation through the Seoul summit.

Economic cooperation topped the leaders’ agreement to boost cooperation: They agreed to accelerate work for a three-way free trade agreement and for inclusion in the 16-nation Regional Comprehensive Economic Partnership. What is noteworthy is that they decided to integrate the three countries into a single digital market by pulling down e-commerce barriers.

North Korea was another highlight of the joint statement issued after the tripartite talks. Both Chinese Premier Li Keqiang and Japanese Prime Minister Shinzo Abe agreed with Park to oppose nuclear arms in the hands of North Korea. The three leaders also agreed to make joint efforts to reopen the six-party talks, which also involve the U.S. and Russia. 

All these positive elements of the summit discussions, however, do not guarantee that the three countries will be able to remain committed to the recognition -- as they pledged in the statement -- that “respective bilateral ties among the three countries constitute an important foundation for trilateral cooperation.”

The three leaders did not have in-depth discussions about the thorny issues of Japan’s historical perceptions and territorial disputes with South Korea and China.

What the apparently qualified statement mentioned was that “the situation in which economic interdependence and political-security tensions coexist must be overcome” and that “in the spirit of facing history squarely and advancing toward the future, we agreed that the three countries should address related issues properly.”

But the case was different in bilateral talks. News reports said that Li and Abe clashed over historical and territorial issues when they met separately after the trilateral summit Sunday.

The thorniest issue between Park and Abe, who sat across the table Monday, was Japan’s military sex slavery during World War II. The two dealt with the issue in the first of the two rounds of talks at the Blue House. 

As expected, they failed to find a breakthrough, with Park’s aides only saying that the two leaders agreed to “accelerate negotiations” for resolving the sex slavery issue. The fact that the two did not hold a joint news conference after the summit indicates the sensitivity of the issue.

Despite the lack of a more concrete agreement on the sex slavery issue, the meeting -- the first-ever between the two leaders -- should provide a momentum to normalize relations between their countries.

Whether Abe will face history squarely, as was noted in the joint statement, will largely determine whether the momentum will be fully taken advantage of.