China’s blessed geography is so obvious a point that it tends to get overlooked in discussions of the country’s economic dynamism and national assertiveness.

Yet it is essential: It means that China will stand at the hub of geopolitics even if the country’s path toward global power is not necessarily linear.

Today China’s ambitions are as aggressive as those of the United States a century ago, but for completely different reasons. China does not take a missionary approach to world affairs, seeking to spread an ideology or a system of government. Instead, its actions are propelled by its need to secure energy, metals and strategic minerals in order to support the rising living standards of its immense population.

Within the Chinese state, Xinjiang and Tibet are the two principal areas whose inhabitants have resisted China’s pull. In order to secure Xinjiang — and the oil, natural gas, copper, and iron ore in its soil — Beijing has for decades been populating it with Han Chinese from the country’s heartland.

The mountainous Tibetan Plateau is rich in copper and iron ore and accounts for much of China’s territory. This is why Beijing views with horror the prospect of Tibetan autonomy and why it is frantically building roads and railroads across the area.

China’s northern border wraps around Mongolia, a giant territory that looks like it was once bitten out of China’s back. Mongolia has one of the world’s lowest population densities and is now being threatened demographically by an urban Chinese civilization next door.

Having once conquered Outer Mongolia to gain access to more cultivable land, Beijing is poised to conquer Mongolia again, albeit indirectly, through the acquisition of its natural resources.

North of Mongolia and of China’s three northeastern provinces lies Russia’s Far East region, a numbing vastness twice the size of Europe with a meager and shrinking population and large reserves of natural gas, oil, timber, diamonds and gold.

As with Mongolia, the fear is not that the Chinese army will one day invade or formally annex the Russian Far East. It is that Beijing’s demographic and corporate control over the region is steadily increasing.

China’s influence is also spreading southeast. In fact, it is with the relatively weak states of Southeast Asia that the emergence of a Greater China is meeting the least resistance.

There are relatively few geographic impediments separating China from Vietnam, Laos, Thailand and Myanmar, and China continues to develop profitable relationships with its southern neighbors. It uses Asean (the Association of Southeast Asian Nations) as a market for selling high-value Chinese manufactured goods while buying from it low-value agricultural produce.

Central Asia, Mongolia, the Russian Far East and Southeast Asia are natural zones of Chinese influence. But they are also zones whose political borders are not likely to change. The situation on the Korean Peninsula is different. No one really expects China to annex any part of the Korean Peninsula, of course, But although it supports Kim Jong-il’s Stalinist regime, it has plans for the peninsula beyond his reign.

Beijing would like to eventually dispatch there the thousands of North Korean defectors who now are in China so that they could build a favorable political base for Beijing’s gradual economic takeover of the region.

China is as blessed by its seaboard as by its continental interior, but it faces a far more hostile environment at sea than it does on land.

The Chinese Navy sees little but trouble in what it calls the “first island chain”: the Korean Peninsula, the Kuril Islands, Japan (including the Ryukyu Islands), Taiwan, the Philippines, Indonesia and Australia.

China’s answer to feeling so boxed in has been aggressive at times — for example when, in March 2009, a handful of Chinese Navy ships harassed the U.S. surveillance ship Impeccable while it was openly conducting operations in the South China Sea.

Beijing is also preparing to envelop Taiwan not just militarily but economically and socially. How this comes about will be pivotal for the future of great-power politics in the region. If the United States simply abandons Taiwan to Beijing, then Japan, South Korea, the Philippines, Australia and other U.S. allies in the Pacific will begin to doubt the strength of Washington’s commitments. That could encourage those states to move closer to China and thus allow the emergence of a Greater China of truly hemispheric proportions.

So can the United States work to preserve stability in Asia, protect its allies there, and limit the emergence of a Greater China while avoiding a conflict with Beijing?

Strengthening the U.S. air and sea presence in Oceania would be a compromise approach between resisting a Greater China at all cost and assenting to a future in which the Chinese Navy policed the first island chain. This approach would ensure that China paid a steep price for any military aggression against Taiwan.

Still, the very fact of China’s rising economic and military power will exacerbate U.S.-Chinese tensions in the years ahead. To paraphrase the political scientist John Mearsheimer, the United States, the hegemon of the Western Hemisphere, will try to prevent China from becoming the hegemon of much of the Eastern Hemisphere. This could be the signal drama of the age.