I think risk aversion partly explains the timid U.S. response to China. In particular, fears of provoking China probably influenced the Obama administration’s decisions.
Several interrelated assumptions underpinned this reluctance to confront China more forcefully. It should be noted that these assumptions informed Obama’s predecessors as well. First, the United States assumed that engagement could coax China into becoming a responsible stakeholder. Second, Washington was convinced that it needed China’s cooperation on a host of global challenges, ranging from climate change to nonproliferation to North Korea. Not surprisingly, preserving stable Sino-U.S. relations was the prime directive while confrontation with China was anathema.