Representatives of more than 3,000 governments and donor organizations are meeting in Phnom Penh, Cambodia, on Wednesday. If past experience is indicative, they will pledge to provide hundreds of millions in aid.

Most of these donors should simply stay home.

Year after year, smiling Cambodian government leaders attend these pledge conferences, holding out their hands. But first they have to listen as ambassadors and aid officers stand at the podium, look them in the eye, and lambast them for corruption and jaw-dropping human rights abuses.

Each year Prime Minister Hun Sen promises to reform. The donors nod and make their pledges — $1.1 billion last year. Then everyone goes home and nothing changes. In the following months, officials dip into the foreign aid accounts and build themselves mansions the size of small hotels, while 40 percent of Cambodia’s children grow up stunted for lack of nutrition during infancy.

This year should be different. Over the past two decades, the Cambodian government has grown ever more repressive. Now it is actually planning to bite the hand that feeds it: The legislature is enacting a law that would require nongovernmental organizations to register with the government, giving venal bureaucrats the ability to shut them down unless they become toadies of the state.

Eight major international human rights organizations are calling on Cambodia to back down, saying the bill is “the most significant threat to the country’s civil society in many years.” Donors, they say, should hold back their pledges. But they say that every year, and each year the donors ignore them. Meanwhile, the status of the Cambodian people the aid is supposed to help improves little if at all. Nearly 80 percent of Cambodians live in the countryside with no electricity, clean water, toilets, telephone service or other evidence of the modern world.

All of this might surprise most Americans. It has been decades since many people here have given Cambodia even a thought. Forty years ago, Cambodia was on the front pages almost every day as the United States bombed and briefly invaded the state during the Vietnam War. Then came the genocidal Khmer Rouge era, when 2 million people died.

How many know what has happened there since? Last month, the Nexis news-research service carried 6,335 stories with Thailand in the headline. Vietnam had 5,196. For Cambodia, 578.

Most people don’t know that Cambodians are ruled by a government that sells off the nation’s rice harvest each year and pockets the money, leaving its people without enough to eat. That it evicts thousands of people from their homes, burns down the houses, then dumps the victims into empty fields and sells their property to developers.

That it amasses vast personal fortunes while the nation’s average annual per capita income stands at $650. Or that it allows school teachers to demand daily bribes from 6-year-olds and doctors to extort money from dirt-poor patients, letting them die if they do not pay.

This is a government that stands by and watches as 75 percent of its citizens contract dysentery each year, and 10,000 die — largely because only 16 percent of Cambodians have access to a toilet. As Beat Richner, who runs children’s hospitals there, puts it, “the passive genocide continues.”

You wouldn’t know any of that from the donors’ behavior. You see, for foreigners Phnom Penh is a relatively pleasant place to live. Rents are cheap and household help is even cheaper. Espresso bars and stylish restaurants dot the river front — primarily for diplomats and aid workers.

Donors have largely been able to pursue whatever project they wanted without interference. They knew that the government would steal some of their money. But so what?

“Some money goes this way or that way,” said In Samrithy, an officer with a donor umbrella group. “But it’s useful if some of it reaches the poor. Not all of it does but some does. That’s better than nothing.”

Even with that, many donors feel the way Teruo Jinnai does. He’s the longtime head of the UNESCO office in Phnom Penh. “Here I have found my own passion,” he told me. “Here, I can set my own target. So that gives you more power, more energy, more passion.”

Well, Mr. Jinnai, the noose is tightening. If, as expected, the NGO bill becomes law, government repression will reach out for you, too. Isn’t it time, then, for all those donors to make a statement? On Wednesday stand up and tell the government: I am withholding my aid.

Joel Brinkley, a professor of journalism at Stanford University, is the author of “Cambodia’s Curse: The Modern History of a Troubled Land.”