BEIJING — For the past seven years, through clouds of construction dust, thousands of meetings, millions of man-hours and an unprecedented political mobilization, China has waited for today.

At $43 billion, the Beijing Olympics, which begin today, represent one of the most expensive coming-out parties in history. And the belle of the ball has a lot to be proud of. China has risen from poverty and social chaos to engineer one of the most impressive economic success stories ever.

With a delegation of 600 athletes, China hopes to punctuate its success with a slew of gold medals between now and the end of the Games on Aug. 24.

"This is such a great moment for China," said Chen Yongming, 55, an engineer and a big track and field, table tennis and swimming fan. "We're very proud of our civilization."

At a time when the government should be beaming, however, it has got the jitters.

An attack Monday on a border police station in distant Xinjiang province, in the nation's far western reaches, killed 16 paramilitary members. The country has seen a wave of protests by foreign activists who managed to enter China despite stepped-up visa restrictions, a strict ticketing system and extensive screening.

Yesterday, China deported two Britons from Students For a Free Tibet who unfurled banners a day earlier near the Bird's Nest stadium, according to a group spokesman, while roughly 2,000 Tibetan demonstrators in Nepal clashed with police while protesting Chinese rule of their homeland.

In response to a speech by President Bush in Bangkok urging Beijing to improve human rights, China's Foreign Ministry called for bilateral dialogue. The ministry added in a statement: "We firmly oppose any words or acts that interfere in other countries' internal affairs, using human rights and religion and other issues."

Meanwhile, the Turkistan Islamic Party, which has threatened to attack Olympic targets, again urged Muslims to stay away from the sites.

And pollution in Beijing remains a source of constant concern for the image-obsessed country, even on good days. Early today saw the city socked in under a heavy cloud of smog.

FAVORED FOR GOLD

In some ways the lead-up almost has set aside the fact that representatives from around the world have gathered for a sporting event. About 10,700 athletes from 205 countries will compete in 28 sports.

China, after finishing second to the United States in gold medals four years ago in Athens, by a count of 36 to 32, could get the most medals this time, experts say.

Chinese sports officials downplay that possibility, saying it is more important that the country host a successful Olympics. Still, seven years ago they implemented Project 119, pulling in new technology, foreign coaches, young recruits and 3,000 sports schools in a national program to make China a sports superpower.

The United States features a typically strong Olympic team led by swimmer Michael Phelps, who, after winning six gold medals in Athens, could break Mark Spitz's single-Olympics record of seven gold medals.

While some expect the early overhang of tension and heavy-handed security to fade once the competition begins, the difficult lead-up has some observers wondering whether this party is worth the price.

In promising a perfect Olympics and pledging to keep protesters and even the weather under control, China has set itself up for disappointment and created a challenge for protesters.

"There's been a drastic change in outlook by the political leadership from 'coming-out show' to 'Let's let the Olympics pass without a crisis,' " said Cheng Li, a senior fellow at the Brookings Institution in Washington. "They've really lowered expectations."

International Olympic Committee President Jacques Rogge acknowledged this week that the Chinese face "some challenges." But he remains at least publicly optimistic about the next 16 days.

"I think history will view the games as a significant milestone in China's remarkable transformation," Rogge said.

LESS THAN ROSY

Seven years ago as Beijing waxed euphoric after winning the bid to host the 2008 Olympics, Chinese envisioned a surging economy, unqualified international praise and an improved media and human rights record that would reverse the stain of the 1989 Tiananmen Square crackdown and cement China's spot at the global table.

While some of this has materialized, the fates, combined with fallout from government policies, have not entirely blessed China despite today's carefully timed opening ceremony linked to a belief in lucky eights — 8/8/08 at 8:08 p.m.

This year has seen a series of food and toy quality scandals, a massive February snowstorm, Tibetan riots in March, torch relay protests in April and the massive Sichuan earthquake in May.

The government also finds itself battling a chorus of foreign critics howling that it has not met the press freedom and human rights commitments it agreed to in 2001. If anything, the government has cracked down harder on critics and activists in recent months to safeguard order and avoid embarrassment.

Predictions of economic bounty after the Olympics seem elusive amid a slowing global and U.S. economy, a softening property market and disappointing tourism figures due to tighter visa policies. And the blue skies that China promised remain frustratingly elusive despite traffic reductions, shuttered factories, cloud seeding and appeals to ancient gods.

Meanwhile, drug scandals have tainted the Olympics for more than three decades. Despite advances in detecting banned drugs, Rogge predicts at least 40 positive tests will be discovered in Beijing.

In America's quest for gold, one of the spotlights will be on the men's basketball team, dubbed the Redeem Team. After a disappointing third-place finish at the previous Olympics, in Athens, this year's team, led by Kobe Bryant, LeBron James, Carmelo Anthony and Dwyane Wade, has done well against international competitors in recent exhibition matches.

Also relentless will be the NBC network, including coverage provided by USA, MSNBC, CNBC, Oxygen, Telemundo and Universal HD. Gymnastics and swimming finals, the marathons and some beach volleyball matches will be held during morning hours in Beijing so American audiences can view them live during prime-time.

Many Chinese believe their country is being held to an unfair standard. Neighboring India attracts far less criticism even as it makes oil deals with Iran, suffers rampant child labor problems and expands its military in line with a booming economy.

Part of the perception gap between China and the outside world reflects its different political culture, emphasis on face and leaders most comfortable at stage-managed events. Still, despite some of its resistance to outside views and criticisms, China is evolving.

"The big picture is China is changing," said Brookings' Li. "But this can be painful. And it comes with big expectations from the outside world in areas where China isn't always ready to change."