If we've learned anything watching our 401(k)s go down the toilet and the stock market take a pistol-whipping, it's that too-lax regulation and the nowhere-to-hide nature of the global economy leave us vulnerable to all sorts of shenanigans.

Need more proof? Three words: China. Food. Melamine.

On Tuesday, the Chinese government ordered all liquid and powdered milk manufactured before Sept. 14 to be removed from store shelves for testing. At issue is the chemical melamine, which apparently was added to dairy products to make them seem more nutritious.

Four babies have died and more than 54,000 kids in China have been sickened by tainted milk products. Over the last month, melamine has turned up around the globe in candies, chocolate, coffee drinks and other items made with Chinese dairy products. Some ended up on American store shelves.

Although many U.S. consumers may not realize it, China is our third-biggest food supplier, after Canada and Mexico.

Melamine, which is used to make plastics and fertilizer, is nontoxic. But it can combine with other chemicals in the body to form crystals that damage the kidneys and cause other problems.

Because melamine is rich in nitrogen, it can falsely register as protein in food-quality tests. This has prompted some unscrupulous Chinese manufacturers to spike dairy products with the chemical in hopes of making their goods seem more nutritious, as was the case last year when melamine in pet food sickened or killed thousands of cats and dogs.

The U.S. Food and Drug Administration has recalled a small number of Chinese-made products. But some lawmakers and consumer advocates say the FDA's measures don't go far enough and have been too slow in coming.

"As soon as this started happening, we called for a ban on all dairy products from China," said Tony Corbo, senior food lobbyist at Food & Water Watch, a Washington advocacy group. "We never got a response from the FDA."

He said his organization was shocked by a recent announcement from the FDA warning consumers not to go anywhere near Chinese-made baby formula but saying that small amounts of melamine in other food products "do not raise concerns."

"I don't think anyone knows if these levels are dangerous or not dangerous," Corbo said. "The FDA did a very quick analysis and came up with a safety standard that may not be realistic."

The agency has determined that 2.5 parts per million represents a "tolerable" maximum amount of melamine that can be safely consumed by adults. But that's far less than some tainted products that have made it to U.S. store shelves.

Last month, the California Department of Public Health warned people not to eat White Rabbit candy imported from China by a San Francisco Bay Area company. Some candies tested by officials contained melamine levels of as much as 520 parts per million.

Stephen Sundlof, director of the FDA's food safety program, said the agency was "looking very closely at imported products that contain milk products from China" but "we have not seen a big problem in the U.S."

He conceded, though, that the 520 parts per million found by California officials was worrisome. "Five hundred is way beyond what we would consider to be safe," he said.

Rep. Rosa DeLauro, a Connecticut Democrat who heads a House subcommittee that oversees FDA funding, said the agency should have followed the European Union in swiftly moving to ban all products potentially contaminated with melamine until the scope of the problem could be determined.

"The FDA has chosen to establish an acceptable level for melamine in food in an attempt to convince consumers that it is not harmful," she said. "Not only is this an insult to consumers, but it would appear that the FDA is condoning the intentional contamination of foods."

I don't know if I'd go that far, but I agree that it's better for authorities to overreact, rather than sit on their hands, when people's lives are possibly in danger.

Most of us had never heard of melamine before pets started succumbing to food containing tainted wheat gluten from China. As with the dairy products, it appeared that melamine had been deliberately added to give the appearance of higher protein levels.

Toys, cribs, drugs -- millions of Chinese-made products have been recalled for a variety of safety considerations, including choking hazards and lead exposure.

This year, a contaminated blood thinner made with Chinese ingredients entered the drug supplies of about a dozen countries and was linked to at least 86 deaths and hundreds of illnesses.

Speaking at a recent economic forum, Chinese Premier Wen Jiabao pledged that Beijing would redouble its efforts to improve product safety. "We will make the entire 'Made in China' brand worry-free and reputable for both the Chinese and the people across the world," he declared.

Similar assurances were made last year when China executed the country's former top food and drug regulator for taking bribes from manufacturers. Yet here we are again.

The answer is more oversight -- not only by the Chinese but also by our own market watchdogs. We need an FDA with both the resources and the wherewithal to keep consumers safe, just as we need financial authorities who can protect us from Wall Street's greedier impulses.

Beijing can spin all the propaganda wheels it likes. The proof's in the pudding. And for all we know, that pudding contains melamine.