While the world seems ablaze with problems, no area or issue, including terrorism, will shape the course of the 21st century for good - or bad - more than the region across the Pacific Ocean: East Asia.

Our next president must thus grasp the full strategic significance of this dynamic region to US interests, even while dealing with the tough problems elsewhere.

No challenge will be a greater for the next chief executive than China's rise as a great power and the ensuing competition for regional and global influence - political, economic and military.

Beijing's crackdown in Tibet and questions about media and political freedoms grab the headlines, but these are just a few on a long list of concerns regarding the People's Republic of China.

Nothing alarms more than China's military build-up. Beijing has the world's third-largest defense budget; it's been rising at 10 percent or more a year for over a decade, making it the world's fastest-growing peacetime defense budget. It'll grow 18 percent this year.

China is using the cash to professionalize its once-antiquated army and to grow the power-projection abilities of its ballistic-missile, air and naval forces. (Indeed, the Chinese navy has the world's most active submarine-building program.) Plus, Beijing is improving its nuclear forces, developing anti-satellite weapons and crafting cyber-snooping and warfare capabilities.

US military planners game the possibility America and China will cross swords over Taiwan, a democratic nation that Beijing sees as a renegade province - and has vowed to unite with the mainland, by force if necessary.

Managing the political relationship won't be easy, either. China is deeply involved with a plethora of pariah states (such as Sudan, Iran, Zimbabwe, Burma and North Korea) which are burrs under America's saddle.

The next prez will also face trade frictions with China, whose juggernaut economy ranks globally as low as fourth (behind Germany) to as high as second (ahead of Japan, but behind the United States), depending on which statistics you use.

The US trade deficit with China (more than $200 billion last year) is a big problem. Americans like cheap Chinese goods, but US firms still face obstacles in doing business in the PRC's controlled marketplace, especially in the service sector.

Then, too, China is the world's largest emitter of greenhouse gases. And heavy pollution isn't just problematic for Olympic athletes - air currents carry it eastward. By some estimates, 40 percent of US West Coast pollution is from China.

Elsewhere in the region, all seems relatively stable on the Korean peninsula. But the fragile peace between the North and South could change in a New York minute, leading to a conflict that would rival the Korean War's devastation.

Tensions have already "hotted up" between Pyongyang and Seoul's new conservative, pro-US government - which seems less likely to coddle irascible, implacable, nuclear-armed North Korea than past Blue Houses.

The United States has made limited headway in rolling back North Korea's nuclear-weapons program. While Pyongyang has made progress in disabling its nuclear reactor, it has failed to come clean on all aspects of its nuke quest.

The more dangerous problem is, arguably, preventing nuclear proliferation off the Korean peninsula to places like Syria - where Pyongyang may have been collaborating with Damascus, leading to Israel's strike on suspected nuclear facilities last September.

North Korea is also tight with Iran, aiding Tehran's growing ballistic-missile program. The Iranian Shahab medium-range missile is a North Korean knock-off; collaboration on intercontinental missiles is likely.

The next prez can't ignore Southeast Asia, either. The Philippines and Indonesia still have potent terrorist threats in the Abu Sayyaf Group and Jemaah Islamiya, each with al Qaeda ties. They have Western targets in their sights, too.

Fortunately, with Washington's help, both Manila and Jakarta have made progress battling terrorism. Indeed, many consider the US-Philippine counterterrorism cooperation begun in 2001 as a model program.

Burma's human-rights record will remain a thorn in the side of US interests, especially while the military junta incarcerates Nobel Peace Prize winner Aung San Suu Kyi and thwarts any turn to democracy.

And don't forget Russia, which deems itself an Asian power. Moscow can't hold a candle to Beijing's new regional clout - but Russia was the Cold War heavy hitter, especially militarily, in that part of the world. The Kremlin will use its plentiful Siberian natural resources and vast oil and gas wealth to throw its weight around with energy-starved Asian powers.

Nor is a Russian-Chinese "condominium" in Asia out of the question: Moscow's done much to aid China's military build-up, selling Beijing the lion's share of its advanced weaponry in recent years - though that's changing now, as the PRC's indigenous arms industry takes off.

Bright spots in the region include America's strong alliance with Japan. Tokyo is making increasing contributions to international security, including a cooperative missile-defense program with Washington.

The plucky Aussies have also been a stalwart ally, not only in their own neck of the woods, but in Iraq and Afghanistan as well, punching above their weight - once again. And while Singapore isn't a US formal ally, our ties are solid.

Many have dubbed this "the Asian century." Considering the region's economic, political and military heft, that may be true - meaning the next White House must keep its sights on East Asia to protect and advance American interests.

Peter Brookes is Chung Ju Yung Fellow and Senior Fellow for National Security Affairs in the Kathryn and Shelby Cullom Davis Institute for International Studies.