Japan’s announcement that it has purchased the Senkaku/ Diaoyu islands has predictably created a firestorm in China. On Saturday, even before Tokyo had announced that a deal had been reached, Beijing was already hinting that the dispute over the islands could impair bilateral economic relations.  Furthermore, after Japan formally announced the nationalization of the islands, China dispatched two civilian patrol ships- reportedly the Haijian 46 and Haijian 49 vessels from the China Marine Surveillance- to “safeguard” Beijing’s sovereignty over the islands. Japan’s Coast Guard responded by deploying its own vessels to the Islands, according to Japanese news outlets.

All of this, while dangerous, is to be expected. What’s more peculiar is the United States’ role in these unfolding events.

From the beginning, it has been clear that Japan has sought to use its alliance with Washington to advance its claims to the islets. Indeed, it hardly seems coincidental that Japanese officials initially began leaking word of the imminent deal while Hillary Clinton was visiting China last week. Additionally, as Chinese media outlets have been so fond of noting, Tokyo’s ratcheting up of tension coincides with a joint U.S.-Japanese military drill.

Washington’s position on the matter has only further muddied the waters. As tensions between Japan and China have increased in recent months, the U.S has insisted that, while it doesn’t take sides on territorial disputes, the U.S.-Japanese defense treaty- which commits Washington to protecting Tokyo’s territorial integrity- covers the Senkaku/Diaoyou Islands. Thus, the U.S. has embraced the same kind of purposeful ambiguity that has characterized its policy towards Taiwan for over three decades.

As the situation has grown even more heated over the past week or so, the U.S. has further divested itself from it. During the Asia-Pacific Economic Cooperation Summit last weekend, Secretary Clinton and the U.S. delegation seemed to touch on every issue besides the Sino-Japanese dispute. The bulk of Secretary Clinton’s comments and energies during APEC were, appropriately enough, devoted to economic issues, particularly promoting stronger economic ties with Russia.

But even though Clinton met with Japanese Prime Minister Noda during APEC, U.S. officials billed this meeting beforehand as intended to address Tokyo’s lingering dispute with South Korea. Little was said about it afterward. Even after Japan announced the deal on Monday, the U.S. merely reiterated its desire to see Japan and China work together to solve the issue through dialogue, unconcerned at the impracticality of this occurring in the near-term.

The ambiguity of the United States’ stance on the dispute makes it difficult to discern what role it is actually playing. Indeed, Washington’s actions over the past week give rise to two widely diverging interpretations. The first, which is the one China will undoubtedly perceive, is that the U.S. is acting as a silent partner in Japan’s misadventures, privately endorsing them while not taking a position one way or the other in public.

On the other hand, the fact that Washington has failed to adopt a coherent position on the issue suggests that Japan may have blindsided the U.S. with the deal, and the Obama administration is still scrambling to come up with a response.

Neither bodes particularly well for the United States. In the case of the former, the U.S. is helping to destabilize the region as China’s state-media has long accused it of trying to do. In the latter case, America’s strongest regional ally is entrapping Washington in its own specific disputes with China, and the U.S. is failing to do anything about it. Given the number of U.S. allies in the region, falling victim to the “tail wags the dog” syndrome could prove extremely costly for the United States over the long-term.

Zachary Keck is the Assistant Editor of The Diplomat.