Many people, like my old friend Brad Glosserman, find it hard to understand why China is acting the way it is in the East and South China Seas. What does Beijing hope to achieve by alienating its neighbours and undermining regional stability? Let me suggest an answer: China is trying to build what President Xi Jinping calls ‘a new model of great power relations’. To understand how this might be the aim of Beijing’s actions, we have to recognise that under his ‘new model’, Xi wants China to wield much more power and influence in Asia than it has for the past few centuries. These things are inherently zero-sum, so for China to have more power and influence, America must have less. This is what Xi and his colleagues are trying to achieve. Their reasoning is simple enough. They know that America’s position in Asia is built on its network of alliances and partnerships with many of China’s neighbours. They believe that weakening these relationships is the easiest way to weaken US regional power. And they know that, beneath the flowery diplomatic phrases, the bedrock of these alliances and partnerships is the confidence America’s Asian friends have that America is able and willing to protect them from China’s power. So the easiest way for Beijing to weaken Washington’s power in Asia is to undermine this confidence. And the easiest way to do that is for Beijing to press those friends and allies hard on issues in which America’s own interests are not immediately engaged – like a string of maritime disputes in which the US has no direct stake.