South Korea's decision to end a military intelligence sharing deal with Japanwill not necessarily have an immediate effect on security.But it could create problems for the South Korean alliance with the United States, experts warn.South Korea announced Thursday that it does not plan to extend the intelligence sharing agreement with Japan.The decision intensified the South's growing trade dispute with Japan.That dispute is rooted in Japan's occupation of the Korean peninsula in the first half of the 20th century.The agreement, the General Security of Military Information Agreement,did not require the two sides to share military intelligence.But it served as a "roadmap" for the control and use of intelligence.The South Korean move shows the United States' lack of influence in East Asia.U.S. officials helped negotiate the agreement in hopes it would help the two Asian countrieswork together on issues involving North Korea, China and Russia.While the two countries still have the ability to share intelligence information, the process will be slower.Much of the intelligence will probably pass through the United States first.That could limit cooperation at a time of crisis.It could also affect efforts to collect information about North Korea's nuclear and other activities.North Korea has launched eight short-range missiles since May.It has also threatened to begin testing long-range missiles."It's not just symbolic. Both sides have too much to gain," says Sung-Yoon Lee.He is a Korea expert with The Fletcher School of Law and Diplomacy at Tufts University in Massachusetts.Japan has the technology to gather information on North Korea's satellites and radar,while South Korea is thought to be better at human intelligence-gathering.But, most importantly, the decision may affect the relationship between the South and the U.S. government.U.S. officials may no longer see South Korea as a reasonable and dependable security partner.Next month, the two sides are to open talks over ways to share the cost of the U.S. military presence in South Korea.U.S. officials want South Korea to spend more.The decision about intelligence sharing makes the situation tenser."It greatly undermines the credibility of South Korea as a security partner in the eyes of the United States," says Bong Young-shik.He is with the Institute for North Korean Studies at Yonsei University in Seoul.U.S. Secretary of State Mike Pompeo on Thursday said he was "disappointed" by the South Korean decision.A U.S. military spokesman said there was "strong concern and disappointment."Both Pompeo and Defense Secretary Mark Esper had said publicly they hope South Korea would not end the deal.In a statement released on Friday, a South Korean official said that his country had"close communications with the United States" as it made its decision to end the agreement.He added that his government will work to make sure the U.S.–South Korea alliance is not weakened.