In a world increasingly driven by advanced technologies, data have become "resources" that countries are competing for. This research paper addresses the question "what is the difference between the data strategies of the United States and China?". Existing literature has a provided comprehensive description of data sovereignty for both China and the United States, but they are usually standard doctrinalcomparative studies. However, this paper provides an additional historical dimension to the doctrinal comparisons. A framework of "spear and shield" is presented to describe how China's data strategy has evolved into a defensive mode while the United States holds an expansive data strategy. The research provides a new frame to understand the data competition between China and the U.S. among other countries. Similar kinds of methods could be utilized in other research on data strategies.