SHANGHAI — At an ocean research center on Hainan Island off China’s southern coast, officials routinely usher visitors into a darkened screening room to watch a lavishly produced People’s Liberation Army video about China’s ambitions to reassert itself as a great maritime power.

As enormous, new naval vessels plow through high seas, a deep male voice intones: “China’s oceanic and overseas interests are developing rapidly. Our land is vast, but we will not yield a single inch to foreigners.”

The 2015 video is one of many signs that China is seeking to emulate the United States’ 19th-century policy of taking exclusive control of security in the Western Hemisphere by excluding foreign powers from the region. Without officially saying so, China hopes to impose a modern version of the Monroe Doctrine on its surrounding oceans.

As formulated in 1823 by John Quincy Adams, then secretary of state to President James Monroe, the Monroe Doctrine said the United States would not accept further colonization by European powers of countries in the Western Hemisphere. Over the succeeding decades, the doctrine came to be interpreted more broadly, culminating with the idea in the early 20th century that the United States regarded the Americas as its exclusive sphere of interest, meaning that it reserved the right to intervene in neighboring countries and would not allow European nations to project power in the region.