North Korea is believed to have used the latest military standoff with South Korea to get inter-Korean talks started so as to win economic cooperation and investment necessary to rebuild its broken economy, a U.S. expert said Wednesday.

The military standoff, which began with the explosion of landmines secretly planned by the North and led later to an exchange of artillery fire across the border, was defused with a peace agreement reached after days of marathon negotiations first proposed by Pyongyang.

"Whatever the motivation for the mine incident was, I think the motivation for the resolution of the crisis was to get a dialogue started again, which is where the North Koreans had suggested in January they wanted to be," Robert Carlin, a North Korea expert, said during a discussion organized by 38 North.

Carlin, a visiting fellow at the Center for International Security and Cooperation at Stanford University, pointed out that the North sent the dialogue proposal the same day its military issued an ultimatum warning of strong strikes.

The inter-Korean deal centered on the South halting anti-Pyongyang propaganda broadcasts in exchange for the North expressing regret over the injuries South Korean soldiers sustained from the explosion of landmines planted by the North.

The two sides also agreed to hold more government-to-government talks to move inter-Korean relations forward, organize a round of separate family reunions around Chuseok -- a major fall holiday in both Koreas -- and seek more civilian exchanges between the two sides.

Carlin said that reviving the economy is believed to be behind the North's push for a dialogue.

"I think that a very consistent theme since Kim Jong-un took office is the focus on reviving the economy. It began with his very first speech in April 2011 where he ... said that people would no longer have to tighten their belts. I think most of his appearances have probably been on economic projects," he said.

"I think he's serious about reviving the economy and one of the best ways to do that is to patch things up with the South Koreans," he said, adding that Pyongyang would like investment from South Korea to balance all the investment from China.

The window of opportunity created by the North's willingness to talk can be short-lived, Carlin said.

"History tells us the windows open and close pretty rapidly .... but a wide open window as there has been for the last few weeks is not likely to stay open that long," he said, adding that Pyongyang could shut the window depending on South Korea's attitude.

Joseph Bermudez, an expert on North Korea's military, noted that the North sent out about 70 percent of its submarines, or about 50 submarines, during the crisis and such capabilities show that Pyongyang's efforts to improve its submarine capabilities produced concrete results.

"The ability to flush your submarine force, and to do it well and quickly, is a demonstration of your level of capability.

Typically, the North Koreans only have two to six submarines out on patrol at any one time. To send out a high percentage of your force, in this case 70 percent, shows a level of readiness," he said.

"It proves to them that the work they've done, the initiatives they had undertaken, the training programs have actually resulted in solid, concrete results," he said.

The North's move could have also been aimed at testing how the South and the U.S. will react, he said.

"They intend that their submarine force be a key component of any future conflict. Knowing how the Japanese, South Koreans, the United States will react to a submarine operations, large scale submarines operations, will help them better plan their operations going forward," he said. (Yonhap)