The hot line between the capitals of North and South Korea was cut last week when Pyongyang began to assume an ever more aggressive posture. However, the hot line that matters as the situation in the Korean peninsular becomes ever more alarming, is that between Beijing and Washington.

China holds the key to peace whereas the United States holds the key to conflict. There are disturbing signs that Washington, fed up with North Korea’s constant nuclear brinkmanship, is prepared to go to the wire on this one. Was it necessary for instance to announce that a missile defense shield was being sent to the Pacific island of Guam to protect Hawaii, or that the US navy had increased the number of warships in the US Pacific Fleet, including a specialized anti-missile deployed off the Korean coast ?

Unlike the Middle East, where America has almost willfully failed to grasp the subtleties and realities of the Arab world, it knows much about the two Koreas and the wider Asia Pacific region. US troops have been stationed in South Korea since the start of the Korean War in 1950. During that terrible conflict, US-led UN forces almost defeated the North Korean communists, until the Chinese intervened decisively and allowed the Kim regime to reclaim most of its lost territory.

Once again Chinese intervention can and hopefully will be decisive, this time in reining back the regime of Kim Jong-un from a potentially disastrous confrontation with its southern neighbor and the United States.

However, the burning question at this crucial time is how closely the Americans are comparing notes with the Chinese. Beijing deplored the third nuclear test conducted this February by Pyongyang, which led to the reinstatement of UN sanctions, which in turn triggered the increasingly bellicose attitude of the North Korea regime. But then China has condemned the previous two underground nuclear tests, as well as the test-firings of a range of medium and long-range missiles which the Kim regime say now bring the United States within targeting range. It does not matter that this rocketry might only be able to reach Alaska and Hawaii. It is enough to anger the Americans, for whom Hawaii is not only the place where President Obama grew up but the location of Pearl Harbor, the Japanese attack on which remains a livid historical scar.

It is generally assumed that since North Korea is reliant on China for significant supplies of fuel and power, not to say foodstuffs, all bought on easy credit, Beijing could bring the Kim regime to heel with a single telephone call. Americans question why this call has not yet been placed. The assumption in Washington may be that as the tensions ratchet ever higher, Beijing will feel itself forced to act. However, this is to assume that the new Chinese leadership is prepared to be forced to do anything.

At the moment Kim Jong-un’s warlike antics are an immediate problem for Washington and its close allies South Korea and Japan. China understandably wishes to challenge America’s near 70 year hegemony in South East Asia. If the Obama administration is choosing to handle the confrontation with Pyongyang in its own way and on its own terms, then the Chinese may be tempted to sit back and let the game play out. The clear danger however, is that the endgame could involve conflict and even nuclear exchanges. Such an outcome would be an utter disaster for everyone involved and moreover would have far-reaching consequences for the entire world.

It is inevitable that certainly at a high diplomatic level, the Chinese and Americans are talking on a daily, perhaps even hourly basis at the moment. But is Obama also having direct contact with his new opposite number Xi Jinping ? And if so, do these two world leaders have anything resembling a plan to head off this terrifying potential confrontation? Some analysts have denied that Washington is saber-rattling, by pointing out that it could be weeks before the new missile shield is deployed on Guam. This may not be true. Installing the ballistic Terminal High Altitude Area Defense System (Thaad) on this island was first mooted in 2009 and it is unclear how much preparatory work was done to receive the missile systems. Indeed the missiles could already actually be in place. However, by broadcasting the delay of weeks, Washington might either have given Pyongyang a window to do its worst or provided the breathing space for negotiations.