A dozen or so gun-laden soldiers from China’s People’s Liberation Army (PLA) stood quietly among the customs agents at Lo Wu Station. The KCR East Rail, the commuter train that left Hong Kong at Tsim Sha Tsui 45 minutes prior, pulled in for its last stop. Shenzhen, once a remote Chinese fishing village nestled peacefully at the mouth of the infamous Pearl River Delta, towered in the distance.

My friends and I exited the train onto the long, cracked concrete platform. A drainage stream littered with rusty steel barrels trickled by. On the northern bank, a retaining wall backed by an even more daunting barbed wire fence served to support the numerous lookout posts dotting China’s most traversed southwestern border. This wasn’t the Rio Grande.

Lo Wu is called a “control point.” I imagine the Chinese authorities used the Korean DMZ as a suitable inspiration.

Consequently, I saw no need to draw the army’s attention. My friends, Western journalists from Hong Kong, certainly weren’t the red-carpet type. So we hung back, letting the hundreds of Chinese scurry by.

The rush for customs ensued. The soldiers, dressed in their long pea-green military topcoats, suspiciously surveyed the masses. And the masses nudged to and fro, like cattle in a stockyard, hoping to find the most expedient line to re-enter the mainland.

My fire engine red North Face duffel bag drew some stares, but Western garb doesn’t fascinate as much in Shenzhen as it would in the more remote, rural regions of northern China. After all, I should thank some among the Chinese hustling all around me for stitching it together. That’s probably also true for just about every item of pure Americana attached to my privileged self. And if the Chinese didn’t construct the authentic item, they could easily point me to an alley where I could haggle the repro.

Shenzhen, Deng Xiaoping’s first attempt at capitalism, Chinese-style, received the elevated status of China’s first Special Economic Zone (SEZ) in 1980. Seemingly overnight, factories popped up along the hot, humid delta like a nasty, uncontrollable case of Southern kudzu. Naturally, more factories required more transportation. Shenzhen became the world’s fourth busiest port by 2005.

Within 20 years, market reforms turned a relatively remote city the size of Green Bay, Wis., into an industrial and financial powerhouse on par with Chicago.

Wal-Mart shelves and Christmas mornings in the West have been built on a 90-hour, six-day workweek in the East. The last 20 years of growth have produced more than 90,000 export-oriented processing firms on the mainland, with nearly 70,000 based in Shenzhen’s Guangdong province alone.

It’s no wonder Chinese officials fear what a slowdown in the export economy may bring. Domestic growth and stability have risen with Chinese workshops. And make no mistake, the first three long-term domestic priorities on Beijing’s list are and will remain stability, stability and more stability.

The yuan-dollar peg has gone a long way in ensuring constancy. Chinese economic growth – we would argue, all economic growth – ensues under the auspice of a stable currency.

But ties to the greenback have recently come with a price. American policymakers have facilitated a weak dollar. The Fed, for its part, announced another $200 billion injection on March 11. Its most recent funding equals the $200 billion Bernanke set free on March 7. For its part, the dollar didn’t know what to think ($400 billion in four days). Or else, it’s in a rather cruel denial.

For the first time since Word War II, owning U.S. Treasuries is a riskier bet than owning German bonds.

On the basis of credit default swaps, which are used to speculate on a government’s ability to repay debt, the 10-year note reached a record high of 16 basis points on March 12. German bonds traded at 15 basis points, also a record. A decline in these spreads shows improving confidence in the government’s ability to pay…an increase shows the opposite.

“That’s certainly eye-opening,” writes our esteemed colleague Chris Mayer. “The market consensus is that you stand a greater chance of default investing in U.S. Treasuries than in German bonds.”

Officials in Beijing must keep shaking their heads. China holds more than $387 billion in Treasury securities.

For China, a weak dollar makes critical imports (wheat, corn, iron and soy) more expensive. Expensive imports mean higher prices. Higher prices mean more inflation. More inflation means less stability.

Chinese Premier Wen Jiabao addressed the equal and opposite reaction on the other side of the planet.

“The primary task for macroeconomic regulation this year,” he decreed, “is to prevent fast economic growth from becoming overheated growth and keep structural price increases from turning into significant inflation.”

In his annual policy speech to China’s legislators, Wen clearly labeled rising commodity prices and the subsequent food shortages as China’s No. 1 policy issue for 2008.

So Beijing finds itself in a bind.

Going forward, yuan appreciation would certainly help alleviate rising prices (commodity imports would be cheaper). Export dependence, however, has thwarted this policy. On the other hand, protecting the export industry by enforcing a close yuan-dollar peg only intensifies further inflation as the dollar continues to slide.

In the meantime, Beijing has turned to price controls. But price controls are nothing more than a short-term stopgap. Price controls disincentivize ample production. Shortages ensue. Prices, therefore, rise even higher.

Beijing may have hope. China’s appetite for consumption keeps growing. We see signs that China’s GDP growth is no longer so export dependent.