As North Korea prepares a potential missile test and issues threats almost daily, the Obama administration is hoping yet again that China can force its unruly neighbor to stand down.
It's a strategy that has produced uneven results over decades of American diplomacy, during which Pyongyang has developed and tested nuclear weapons and repeatedly imperiled peace on the Korean peninsula.
But with only the counterthreat of overwhelming force to offer the North Koreans, the U.S. has little choice but to rely on Beijing to de-escalate tensions in a peaceful manner.
The question of how Washington can persuade Beijing to exert real pressure on Korean leader Kim Jong Un's unpredictable regime is front and center as U.S. Secretary of State John Kerry conducts a series of meetings Saturday with Chinese leaders in Beijing.
Kerry is expected to discuss how to defuse the situation with President Xi Jinping, Premier Li Keqiang and other top members of China's communist leadership.
The immediate crisis: a North Korean test of a mid-range missile with a range of up to 2,500 miles that the U.S. believes could happen any day. The long-term problem: a nuclear program that may soon - or already - include the capability to deliver a warhead on a missile.
China is the only country with significant leverage over North Korea, a regime that like few in the world actually cherishes its isolation.
The Chinese have dramatically boosted trade ties with their neighbors and maintain close military relations some six decades after they fought side by side in the Korean War. They provide the North with most of its fuel and much of its food aid.
But Beijing, which values stability in its region above all else, clearly has different priorities than Washington. China's greatest fear is the implosion of North Korea's impoverished state and the resulting chaos that could cause, including possibly millions of refugees fleeing across the border into China.
For that reason, China has in many ways looked past North Korea's bellicose rhetoric and activity, prioritizing the security of Kim's regime - like his father's and grandfather's previously - over nuclear proliferation concerns.
"China's main interest in North Korea is not denuclearization; it is ensuring that the North Korean government does not fall," Asia expert John Pomfret wrote in a recent opinion piece.
"While Beijing might be exasperated with the Kim dynasty's uncanny ability to wag China's dog, China will support Pyongyang because the alternative, a North Korean collapse, is worse," he wrote. "While many South Koreans fear the cost of unification with their brothers to the north, China opposes that even more stridently."
China also remains deeply wary of any American military buildup in its backyard, suspicious that the containment effort toward North Korea may be part of the long-term U.S. strategy to expand its influence in the region and even ring in fast-growing China with countries closer to Washington.
U.S. officials say they've gone to great lengths to explain to China that the American objective in North Korea - at least in the short term - is not regime change.
While the U.S. abhors the North's human rights record, its regular provocations and military links with other international pariahs such as Iran, it has stressed over years of conversations with Beijing that pushing for North Korean denuclearization could reinforce stability.
In Seoul on Friday, Kerry said President Barack Obama had canceled a number of military exercises planned with South Korea. The message was directed as much to Pyongyang as Beijing that the U.S. wasn't seeking a military confrontation.
"I think we have lowered our rhetoric significantly and we are attempting to find a way for reasonableness to prevail here," Kerry told reporters. "We are seeking a partner to deal with in a rational and reasonable way."
The Obama administration believes it may now have greater scope for diplomatic progress. It has pointed to Xi's recent criticism of Pyongyang as illustrative of a subtle shift in China's outlook. Beijing also has backed U.N. sanctions in response to North Korea's tests of a nuclear device and intercontinental ballistic missile technology over the last four months.
But, U.S. officials say, China has refused to stamp out business between its companies and North Korean entities under American sanctions. And it has failed to eliminate the flow of funds to North Korea's weapons of mass destruction program.
And even as North Korea has issued outlandish threats including nuclear strikes against the United States, American officials say they aren't even considering asking China to slow its burgeoning trade and investment ties with its neighbor.
The U.S. is in somewhat of a bind. It wants the Chinese to do its bidding, but it cannot push too hard, given that the U.S.-China relationship is of paramount importance to global security and the world economy. The U.S. and China are the world's two biggest economies.
On the one hand, U.S. officials blame China for continuing to provide North Korea protection for its provocations. Yet they also claim China's position is moving closer to the rest of the international community, even if that's had little impact on the North's behavior.
Pomfret pointed to President George W. Bush's memoir as a lesson of China's true objectives. Bush described how in October 2002 he invited then-President Jiang Zemin to his ranch and asked for China's help to prevent North Korea from developing nuclear weapons.
Jiang, Bush said, told the American leader that "North Korea was my problem, not his." Only when Bush threatened a military strike against the North did China react differently, Bush wrote.
Six-party denuclearization talks started soon after, but they didn't solve the problem. By 2006, North Korea was a nuclear power.
United News of Bangladesh