US Defense Secretary James Mattis assured South Korea on Thursday about the robustness of the bilateral security alliance linking the countries, at a time when the threat underpinning the presence of US forces in Korea – a North Korean military assault – appears to be receding.

Mattis’ visit came one day after the outgoing US commander in Korea, General Vincent Brooks, had addressed senior military colleagues on the issue, while experts debated the same issue at a high-profile forum in central Seoul sponsored by Seoul’s Ministry of Unification.

While the Americans seemed keen to assure Seoul of continued support at a time when US President Donald Trump has made conflicting statements on the issues, other experts suggested that the bilateral alliance – founded on the idea of supporting South Korea against a North Korea attack or invasion – is outdated and could even be a cause of regional friction.

But with China and Russia ideologically conflicted with the United States, and its Japanese and South Korean partners, the concept of a wide security architecture in Northeast Asia seems far off.

An ‘iron-clad’ commitment

“The US commitment to the Republic of Korea remains iron-clad,” Mattis, who was in Seoul between stops in Beijing and Tokyo, told South Korean Defense Minister Song Young-moo on Thursday, according to Reuters. Mattis also said he would maintain the strength of US troops on the peninsula, known as United States Forces Korea, or USFK, at the current level of 28,500.

His visit comes after US President Trump promised North Korean leader Kim Jong-un, during their summit in Singapore, a halt to what he characterized as “provocative” and “expensive” military exercises. That commitment took both Seoul and the USFK by surprise.

While the liberal Moon Jae-in government in South Korea quickly agreed to the indefinite halt, Moon has repeatedly backed the overall alliance. But the halt sent jitters through conservative circles in South Korea, who customarily bristle at any signals that the bilateral alliance may be in any way downgraded.

Seoul’s military partnership with the US takes the form of both a paper agreement and a physical presence.

The two countries are bound by a Mutual Defense Treaty, and South Korea hosts a major US force on its own soil. Cost-sharing talks are now underway between the two sides on the cost of USFK, which is currently in a process of redeployment from near the DMZ and Seoul to a massive new hub, Camp Humphreys in Pyeongtaek, south of the capital. Brooks called that base “a great gift form the Republic of Korea.”

South Korea has no military alliance with any other country, which is why when Trump talks of military costs and his desire to bring troops home, hackles can rise.

Toning down ‘intimidating’ war games

Speaking the day before Mattis’ visit, Brooks talked of the need to move the ongoing engagement process with North Korea forward, without being bound to the past.

“There is always a case for pessimism, but if you want to be more focused in times of uncertainly, you must take some risks and move forward,” Brooks told a meeting of senior South Korea and US military officers and reporters on Wednesday. “I don’t discount reasons for doubt, but we are in a unique place now. We must move forward to make history, not rely on it.”

He conceded that there was political pressure to tone down military preparedness measures. “We must be in a ready posture, but do so quietly,” he said. “This is a sharp sword that is no less dangerous when it is put in its scabbard.”

Regarding the surprise announcement on the indefinite halting of scheduled summer drills, he said that leadership development training and smaller exercises could continue, but suggested various ways to tone down major exercises in terms of scope, scale, timing and communications volume.

And he admitted that exercises are about more than readiness: “They can have a messaging component to them – deterrence or intimidation,” he said.

Regarding US troops in Korea, he said: “We should not have worries or doubts about the departure of USFK.”  However, he added: “I have no guarantee how long it will last … if there is an end, it will be the time when the alliance is no longer needed. It is not today, it is not next week.”

While he noted that the North Korean threat had not yet receded, its behavior had improved. In his first 17 months on the peninsula, there had been some 50 provocations from North Korea, but in the last six months, there had not been one. “I could not have imagined that,” he said.  

US-South Korean alliance in question

Other experts shared Brooks’ surprise. “I believe Kim Jong-un has made a strategic decision,” said Joseph DeTrani, a former CIA executive and Washington’s former envoy to the now-defunct, Beijing-sponsored six-party talks. “He made a decision to improve the lives of the people. He had proved he had a nuclear deterrent.”

The latter is a reference to Kim’s signature dual-track policy of nuclear arms and economic development, and his apparent abandonment of the nuclear component since his ground-shaking New Year’s Day speech.

Still DeTrani, who was talking at the Seoul Global Forum 2018, held at the Samsung-run Shilla Hotel in central Seoul, admitted that while nuclear monitors now have excellent soil and water sampling technologies, the litmus test of North Korean sincerity when it comes to denuclearization will be whether monitors are allowed freedom of movement to investigate suspected sites in North Korea.

Hitoshi Tanaka, Chairman of the Institute for International Strategy at the Japan Research Institute, who was also at the forum, said he would “rest assured” about Kim’s sincerity if he produces a full listing of nuclear sites in his nation.

While hopes are high for the process, risks are also high, warned Chen Dongxiao, President, Shanghai Institute for International Studies, another forum speaker. While he noted the “game-changing effect of summit diplomacy,” Chen said: “If we have unrealistic expectations of this process, it will make things more dangerous than before. There is a Korean saying, ‘a good beginning is half done,’ but the second half of the mission is more arduous.”

Even if North Korean denuclearization does proceed smoothly, the broader question of regional security remains unresolved.

“There is no security coordinating mechanism in the region, each country has different interests,” said Tanaka. “I give credit for the six-party talks: I can’t think of any other mechanism in the region.”

One lesser-known component of those talks was on regional security frameworks. While DeTrani suggested a bilateral alliance does not preclude multilateral alliances, Chen was skeptical.

“I recognize the role played by the US alliance during the Cold War era, but one obvious weakness of an exclusive, ideologically-oriented alliance is it makes the region very polarized,” said Chen. “NATO’s expansion is one of the main reasons for the escalation of tensions between Russia, NATO and the US.”

However, though he conceded there was a need for a broader regional security system, Chen added: “Realistically, China will not be an ally of the US.”

And with Beijing flexing its muscles across the region, it is not only Seoul that is jittery about a reduced US footprint: Tokyo is equally, if not more, concerned.

“Normal, conservative governments in the US … place emphasis on the alliance and forward deployment, but Trump is very different: It is about money!” warned Tanaka. “If the US-South Korea alliance ends, Japan is the front line. We will have to expand our military capability. We should not have a power vacuum here.”