WASHINGTON -- Increasingly frosty relations between South Korea and Japan lately are impeding U.S.-led efforts to bolster regional preparations for responding to a potential future North Korean attack, current and former U.S. and Japanese officials say.
"We can't afford for our allies to be on divergent paths," said David Asher, a former senior adviser on East Asian affairs at the State Department.
The United States would like to see the Japanese and South Korean armed forces deepen their collaboration against possible threats from Pyongyang, especially those posed by fast-flying missiles. However, several initiatives in that area have been stymied by historic -- and newly mounting -- distrust in Seoul about Tokyo's military ambitions.
South Korea has raised concerns over the Shinzo Abe administration's plans to expand Japan's definition of "collective self-defense" to include coming to the aid of allies besides the United States. Seoul has yet to approve a proposed bilateral accord that would authorize the exchange of military intelligence on such things as ballistic missiles fired by North Korea.
While the United States has separate agreements in place with Japan and South Korea that allow for the dissemination of technical information about North Korean threats, there is no accord in place that allows for the seamless transfer between Seoul's and Tokyo's militaries of similar data.
"It's essential … that we have a common intelligence and reconnaissance operating picture and operating strategy," Asher said in a phone interview last week, referring to Japan, South Korea and the United States. "The inability to share information among our alliances inhibits that and therefore leads to increasing dysfunctionality."
Seoul had been expected to approve the military intelligence pact in summer 2012, but abruptly delayed its signing after a number of local lawmakers objected to what they saw as a rush by the former Lee Myung-bak government to approve the accord without allowing enough time for public debate.
A meeting earlier this month between the South Korean and Japanese vice defense ministers failed to produce any announcement on when the accord might be finalized.
Seoul is also uncomfortable with Tokyo increasing the number of scenarios in which it is willing to intervene militarily abroad. However, Washington views it as only natural for Japan to take on a broader role in regional defense that is commensurate with its financial clout, according to James Schoff, a former Pentagon official specializing in East Asia issues.
This would constitute a major change. Japan's current pacifist constitution, adopted shortly after World War II, permits the Pacific power to use its sophisticated military only to repel attacks against Japanese territory.
Kyodo News reported last month that a South Korean Foreign Ministry spokesman stated that talks with Tokyo about its assertion of a right to collective self-defense should take place "under the basic principles of the pacifist constitution and in a way that alleviates the concerns that neighboring countries have for historical reasons."
Some officials in South Korea are concerned that under the proposed revised defense doctrine, Japanese forces could unilaterally deploy to the Korean Peninsula, for instance, following a possible sudden collapse of the Kim Jong Un regime in North Korea, according to a separate Kyodo report from November.
Such a scenario is disturbing to some in South Korea where the memory of living under Japanese colonial rule has not faded. Seoul also hopes to reunify the two Koreas and is concerned this goal will be complicated if Japanese troops deploy to the North.
Ji-Young Lee, an assistant professor at American University's School of International Service, last week said she believed it would be more prudent for the Japanese military to play a logistical support role in any allied plan for dealing with the chaos of a post-Kim North Korea, rather than deploying any troops to the Korean Peninsula.
"That's why it is so important to have prior consultations" among Seoul, Tokyo and Washington on plans for addressing possible regime collapse, said Lee, who focuses on East Asia security issues.
Asked for comment on the matter of trilateral discussions, State Department spokesman for East Asian and Pacific Affairs Jason Rebholz said Washington and Tokyo in senior-level October talks "affirmed the importance of coordinating closely" with Seoul on common defense matters.
"I think the United States in private certainly tries to convince South Korean counterparts that this is OK, because this is about Japan contributing more to regional security," said Schoff, who is now with the Carnegie Endowment for International Peace.
Many in South Korea think that Japan has not gone far enough in apologizing for its colonization of the Korean Peninsula in the early 20th century or its actions during World War II. This sentiment has only deepened over the last year as a result of actions by the Abe administration, such as visits by cabinet members to a shrine that honors Japanese killed in the war, including a number of convicted war criminals.
"If Germany had continued to say things that inflicted pain, while acting as if all was well, would European integration have been possible?" South Korean President Park Geun-hye was reported by the New York Times to have said to U.S. Defense Secretary Chuck Hagel during a September meeting. "I think the answer is no."
Hagel had reportedly hoped to use the meeting to prod the South Korean leader into adopting a softer line toward the Abe government, but was unsuccessful.
Comments by Japanese politicians about the country's colonial and World War II-era actions "really fuels" fears among some South Koreans that Japan might resume its 20th century militarism "if [Japanese leaders] say things that indicate that Japan" is not truly remorseful about the past, Lee said.
Abe "understands very clearly" that having a good relationship with South Korea is important, particularly "because of the North Korean issue," said a Japanese government official, who lacked permission to discuss the sensitive matter and asked not to be identified.
In a November interview with Global Security Newswire, the official acknowledged that "because of the difficulty in [bilateral] relations, a lot of cooperation and technical issues have also been stalled."
Sung-yoon Lee, an assistant professor of Korean Studies at Tufts University's Fletcher School of Law and Diplomacy, said it is past time for Abe and Park to hold their first summit and discuss their governments' respective roles in a possible post-Kim North Korea.
"I understand that politically it's not feasible for the South Korean government to address those issues in public," said the Fletcher scholar in a recent phone interview. "At the same time, I think the government is being myopic in not addressing these issues behind closed doors" in trilateral talks with Japan and the United States, he said.
The South Korean military is generally more supportive of deepening cooperation with Japan than are South Korean politicians, according to experts.
"I think there is a better mil-to-mil working relationship between [South Korea] and Japan than realized by most people," said Asher, who is now a non-resident senior fellow with the Center for a New American Security. "It’s at the high level where things are really troubled."
Added Schoff last week: "South Korean defense leaders would love to get this [intelligence-sharing pact] done, so they would have access in real-time to the X-band radar information coming out of Japan."
The U.S. deploys an early-warning radar at the Shariki military base in northern Japan and is planning on fielding a second, long-range sensor within the year at the Kyogamisaki air base. The radars will be focused on improving the early detection and monitoring of potential North Korean ballistic-missile launches.
Having immediate access to X-band data about any possible North Korean missiles heading toward South Korea could give Seoul a bit more time to ready a response to any attack, according to Schoff.
Given a perception that the threat posed by North Korea is increasing, it "is very important" to finalize the bilateral intelligence accord, the Japanese official said.