Want to know what a world in which American power is in eclipse will look like? Just look around, from Ukraine to the South China Sea–both places where powerful states are seeking to dominate their neighbors with military force. 

The Ukrainian story is by now well known, with Russia having annexed Crimea and is in the process of setting up independent statelets in eastern Ukraine. But also of great significance is the recent decision by a Chinese state-owned National Offshore Oil Company to plant a $1 billion oil-drilling rig just 130 miles off the Vietnamese coast in waters that are claimed by Vietnam as an exclusive economic zone. Accompanying the oil rig were as many as 80 vessels belonging to the Chinese navy and coast guard; they used a water cannon to ward off a Vietnamese ship that got in the way of their power grab.

This Chinese move, into territory over which its jurisdiction under international law is virtually nonexistent, is all the more egregious because just three years ago Beijing and Hanoi reached agreement on shared borders and maritime rights. Now China is unilaterally abrogating that agreement and daring Vietnam and the rest of the world to do something about it.

So far, just as in Ukraine, so in the South China Sea, the rest of the world–led by the U.S.–is hardly a profile in courage. Vietnam tried but failed to get its neighbors, meeting last weekend at the Association of Southeast Asian Nations, to condemn the Chinese move; those states are too scared of China to speak up publicly. The State Department, for its part, issued a pro forma denunciation of the Chinese move and left it at that.

Beijing is unlikely to be impressed. This was widely seen as a test of American and regional resolve to stand up to Chinese attempts to dominate waters that are also claimed by its neighbors. The lesson that Beijing must take away is that, just like Moscow, it has a green light for further aggression. 

The great danger here is that, just as in Europe, the local bully may miscalculate; one of its neighbors–whether Vietnam or Japan or the Philippines or some other state–may actually stand up to China and the result could be a shooting war. 

Although this is a regional dispute, just like the ongoing events in Ukraine, it has global ramifications, because it highlights the power vacuum being left by the present administration’s ill-advised retreat from America’s global leadership.