The U.S. is ratcheting up diplomatic efforts to defuse tensions on the Korean Peninsula, even hinting at a concession to China on missile defense, as North Korea’s brinkmanship adds to Washington’s already daunting international and domestic challenges.

During his tour of South Korea and China last week, U.S. Secretary of State John Kerry called for dialogue with Pyongyang and apparently urged Beijing to do more to rein in its ally. He indicated that the U.S. was willing to scale down missile defense if the security threat in the region eased.

Experts said the U.S. was seeking to prevent peninsular tensions from escalating into a greater security crisis. Some argued America’s domestic problems might have forced Washington to avoid an escalation of the standoff.

“President Obama ordered a number of exercises not to be undertaken. I think we have lowered our rhetoric significantly, and we are attempting to find a way for reasonableness to prevail here,” Kerry said during a press conference in Seoul on Friday.

His remarks came about a week after the U.S. put off its plan to conduct an intercontinental ballistic missile test at its air force base in California out of concerns the Minuteman III test could further escalate tension with the North.

During his stop in China, Kerry went further, indicating that should North Korea renounce its nuclear programs, the U.S. would reduce its newly beefed-up missile defense systems that China and Russia have apparently felt uneasy about.

“Now obviously if the threat disappears ― i.e. North Korea denuclearizes ― the same imperative does not exist at that point of time for us to have that kind of robust, forward-leaning posture of defense,” Kerry said in a news conference in Beijing. “It would be our hope in the long run, or better yet in the short run, that we can address that.”

Analysts said the offer of a missile defense concession appeared aimed at putting more pressure on China, the North’s only major ally and patron, to exert more influence on its recalcitrant neighbor to change its current provocative course.

The U.S. has recently unveiled its plans to deploy a land-based “terminal high-altitude area defense system” to Guam as a “precautionary” move and to strengthen its missile defense against the North by installing 14 additional ground-based interceptors at its bases in Alaska and California by 2017.

Seen preparing to test its intermediate-range Musudan ballistic missile, the North has threatened to strike U.S. bases in South Korea, Japan and Guam. The missile in question, with a range beyond 3,000 km, is known to be capable of reaching Guam.

A security expert said the U.S. appeared to be “controlling its speed” in handling the provocative North after it showed off its deterrence capabilities by mobilizing most of its nuclear capable strategic assets such as B-2 stealth bombers and a nuclear-powered submarine.

“After showing off all that, Washington might think it no longer needs to do anything that would further escalate tension. The U.S. appears to be controlling its policy tempo in handling the North,” he said, declining to be named.

Kwon Tae-young, adviser to the nonprofit Korea Research Institute for Strategy, said Kerry communicated a message to China to step up coordinated efforts as escalated tension would not serve anyone’s national interest.

“As the North threatened to turn Washington and Guam into a sea of flames, it cannot help but step up its missile defense, which apparently posed a headache for China and Russia,” he said.

“Kerry signaled should such threats disappear, the U.S. would scale down its military presence.”

Given a series of domestic issues facing the second-term Barack Obama administration, Washington might want to avoid any instability on the strategically crucial Korean Peninsula, particularly after a decade of war in Iraq and Afghanistan, analysts pointed out.

In addition to the across-the-board federal spending cuts, or sequestration that went into force last Month, the Washington faces a host of politically sensitive domestic issues such as immigration reform, and gun ownership and control, not to mention global security conundrums such as Iran-related issues.

Whatever the reasons behind the efforts to calm tension here might be, Washington’s moves to step up cooperation with China comes as Beijing itself does not want to see its wayward neighbor continue to make trouble.

“Basically, neither the U.S. nor China wants another war on the peninsula. What matters for both is the nuclear issue surrounding the North, which has clarified it will not abandon its nuclear program,” said Sheen Seong-ho from the Graduate School of International Studies at Seoul National University.

“The U.S. stance is that it will not recognize the North as a nuclear power, but in realistic terms, without a war, it would be difficult for it to dismantle the North’s nuclear program. So it wants to prevent the North’s nuclear proliferation while taking measures to deter its provocations.”

With the U.S. moving to increase cooperation with China in pressuring the North, some observers said Seoul might need to caution against losing “its strategic influence” over Pyongyang.

Amid worsening cross-border ties, inter-Korean dialogue channels have been shut down with the fate of the Gaeseong industrial complex now hanging in the balance. To take the initiative in the multilateral efforts to entrench durable peace, Seoul needs to maintain some leverage over Pyongyang, experts argued.

By Song Sang-ho (sshluck@heraldcorp.com)