SEOUL (BLOOMBERG) - In opting to "completely" restore cooperation with Japan after a more than three-year hiatus, China and South Korea chose to prioritise economic and security issues over the disputes about history and territory that have divided them.

The detente may prove fragile.

After their weekend meeting in Seoul, South Korean President Park Geun Hye, Japanese Prime Minister Shinzo Abe and Chinese Premier Li Keqiang pledged to cooperate "unwaveringly" in a communique after the talks. The statement barely touched on the lingering bitterness over Japan's past militarism that has stymied cooperation and led to the three-year suspension of trilateral summits.

All three countries face slowing economies and renewed threats from a nuclear-armed North Korea, whose missiles can reach Seoul, Beijing and Tokyo. The shifting landscape seems to have tilted the balance toward building a united front and the leaders made a collective pledge to revive talks on a free-trade agreement that would cover about one-fifth of the global economy, and called for the restart of disarmament negotiations with the Kim Jong Un regime.

"Nobody is under any illusions that summits are like a magic wand, but there is a lot of low-hanging fruit that leaders can focus on to launch confidence-building measures in a region brimming with tensions," said Jeff Kingston, director of Asian studies at Temple University's Japan campus.

"It's key now to quickly follow up the summit with some tangible initiatives that will provide an opportunity to shift more controversial issues off the front burner," he said.

- SEEKING 'SINCERITY' -

The bickering over decades-old grudges was muted, and there were some signs that Park and Abe were prepared to work together in resolving one of the thorniest issues dividing them.

In the first bilateral meeting between leaders of South Korea and Japan in more than three years, Park and Abe agreed to accelerate talks on resolving the issue of the so-called comfort women who were trafficked to Japan's military brothels before and during World War II. Japan is considering an expansion of financial aid to support the women, the Nikkei newspaper reported on Tuesday (Nov 2) without attribution.

Park had previously refused to meet with Abe until he did more to atone for Japan's treatment of the women and show more "sincerity" in responding to the survivors, who number fewer than 50 in South Korea.

Abe said after the meeting that it was imperative to ensure that the issue didn't fester and "hurt future generations" though there was little sign that the bilateral talks did much to bridge the gap.

Back in Japan after the summit, Abe said on a TV appearance that it would be extremely difficult for the people of both countries to be perfectly satisfied with attempts to resolve the comfort women issue, but that an agreement can be found if talks continue.

- 'GOOD' ATMOSPHERE -

The atmosphere was "good" and there were "no emotional scenes" during the Abe-Park summit, which lasted a total of an hour and 45 minutes, according to Deputy Chief Cabinet Secretary Koichi Hagiuda who was present during the talks.

China and South Korea's relations with Japan were already strained before Abe came to power, and they deteriorated further under his administration. Both countries have territorial disputes with Japan over two chains of desolate islands, and bitterness toward Japan over the war and its 35 years of colonial rule on the peninsular still run deep.

Abe has also fuelled that animosity. In 2013, he visited a Tokyo shrine seen by many in Asia as a symbol of Japan's past aggression; and this summer he stoked fears of a revival of Japanese militarism in the region by pushing through legislation to expand the role of his nation's armed forces.

Polls indicate that Abe is about as unpopular in South Korea as Kim Jong Un, and police were out in force during the summit through demonstrations were small.

The tensions over the war ran particularly high this year, which marked the 70th anniversary of the end of the conflict. Both countries celebrated holidays marking their liberation from Japan.

- WAR ANNIVERSARY -

"The year of 2015, which has been heavily marked by the war theme because it's the 70th anniversary of the end of the World War II, is passing," said Wang Xinsheng, a professor of history who specialises in Japan and East Asian politics at Peking University.

"Now comes a chance for the three to put their focus back to economic cooperation and trade."

Shifting that focus may could help accelerate a trilateral trade agreement between the countries - talks on which bogged down as their relations soured. China is the biggest trading partner of both Japan and South Korea.

"A trilateral FTA amongst the three North Asian economic powers would be a significant boost to long-term Northeast Asian trade and investment flows," said Rajiv Biswas, Asia-Pacific chief economist at IHS Global Insight in Singapore.