By Elise Labott

After weeks of fiery rhetoric, military saber rattling and threats against the United States and South Korea, North Korea seems downright quiet and willing to dial back the tension.

Fears Kim Jong Un would test a long-range missile have given way to an easing of his daily war threats, and North Korea has produced a list of conditions for dialogue.

In exchange for returning talks, North Korea wants the lifting of U.N. sanctions, the end of the U.S.-South Korea military drills, the withdrawal of U.S. nuclear strike capabilities from the region and a halt on criticism of the North. It also wants a South Korean apology for offending its leadership.

Still, even the subtle shift in tone is an improvement to the war footing Pyongyang was on just weeks ago.

So what gives?



It could just be the well-oiled pattern by the North in which hyper threats and provocations, such as nuclear and missile tests, are typically followed by a cooling off period in which the regime sits back and waits to be rewarded for backing down.

Moreover, U.S.-South Korea military drills ended Tuesday, which were a major cause of North Korea's angst.

Photos: Militaries and Korean tensions

But Korea watchers also know the road to North Korean compliance runs through Beijing.

During his trip to Asia last month, Secretary of State John Kerry placed premium importance on getting China to rein in North Korea.

While in the region Kerry said China had a vital role to play in getting North Korea to abandon its nuclear weapons, calling China the "lifeline to North Korea."

"I believe China needs to become more engaged in this effort," Kerry has said since visiting Beijing. "Absent China coming to that table, I believe President Kim Jong Un calculates, literally calculates, that 'I can get away with anything if China isn't going to hold me accountable.'"

China, North Korea's largest economic partner and most important political backer, has been reluctant to pressure the North Korea.

China's main fear is that a collapse of the Kim regime could see the unification of the Korean Peninsula, which could put the American military at its doorstep. Beijing also doesn't want thousands of refugees crossing into China.

But after North Korea ignored China's warnings last December against launching a rocket into space, Beijing started losing its patience.

Then, after North Korea launched its third nuclear test in February, China supported stiff economic sanctions at the United Nations.

"Beijing's messages are not getting through and that is causing concern," one senior official said. "We think that is the main aspect for China's actions. And sure our diplomacy is playing a role as well."

Nuclear weapons: Who has what?

In recent months there has been an open and critical debate in China over its relationship with North Korea, which would have been unthinkable only a few years ago.

Once a politically sensitive topic considered off limits, online columnists and Chinese on social media now open ponder the question of whether China's relationship with North Korea should be sacrosanct.

"For the first time in years, there is reason to hope China may be more helpful. Beijing is clearly exasperated with the North. The new Chinese leader, Xi Jinping, is more decisive than his predecessor. His new foreign policy team views Pyongyang with a jaundiced eye after years of mopping up the diplomatic messes," wrote Michael Green, Victor Cha and Christopher Johnson in a CNN blog post.

The writers are all former U.S. officials who now work at the Center for International Strategic Studies.

Kerry's warm public talk about China's helpfulness came, however, with tough talk and a not-so-subtle threat: reign in the North Koreans or expect the U.S. military buildup in the region to continue.

Obviously, if the threat disappears, the same imperative does not exist at that point in time for us to have that kind of robust, forward-leaning posture of defense," Kerry said in Beijing, referring to a nuclear-free North Korea. "And it is our hope in the short run that we can address that."

There are small, but encouraging, signs that Beijing got the message and is ready to work seriously with the U.S. on diplomatic efforts to rein in the North Korean nuclear weapons program.

South Korea: Joint military drills with U.S. over, but vigilance on North remains

Wu Dawei, China's special representative for North Korea policy, visited Washington this week for several days of consultations with Glyn Davies, the State Department's envoy for North Korea. U.S. officials say Davies is expected to meet with Wu again in Beijing next month.

Transfers of money from North Korean entities in China back to Pyongyang have slowed, as have customs checks at the borders, according to experts and officials. U.S. officials say that China has taken additional measures to crack down on the North, but would not be specific about them in order to build trust with their Chinese counterparts.

How much Kerry's backroom diplomacy with China was a factor in North Korea's calmer behavior has yet to be determined. Some U.S. officials acknowledge China is singing a helpful tune, but have yet to see serious moves by Beijing that would indicate they are putting serious pressure on the regime.

"We believe the views the Chinese have expressed publicly about North Korea are also being expressed privately," one senior U.S. official said. "Whether they are having an effect on North Korea, we don't know. I don't think we can say it's promising or not at this stage."

Other factors are also at play. Spring is typically the time of year North Korea's military returns to the fields for planting. With North Korea's economy in tatters, the military does double duty as farmers, laborers and manufacturers.

And there is the unfortunate realization that North Korea's time out, however welcome, is just that - a time out. Although Pyongyang is undoubtedly pleased the U.S.-South Korea military exercises are over, officials and experts are worried North Korea will feel more emboldened once again.

"This can go on for months with North Korea where nothing is happening or tomorrow they could launch a missile," one senior U.S. official said.