China is pushing outward. The country has made steady moves to reclaim its role as the pre-eminent power in the Pacific Rim. This expansion, however, differs from those made at any other time in its history. For most of China's existence, it was a continental power endowed with sufficient resources with an economy driven by self-contained markets. External trade was a factor but moved mostly by land, primarily via the Silk Road. Sea trade also did occur, but China's coast was generally a liability — a point of incursion to protect from raiders and hostile powers. China was not compelled to explore the seas and seek new lands. Until recently, modern China hewed to this pattern. This began to change by the late 1990s, when China's economic boom started to strain domestic resources.