While the presidential candidates fruitlessly argue over how to handle immigration, there should be no debate over welcoming one category of immigrants:

Afghan interpreters who risked their lives by working for U.S. soldiers and civilian officials.

Indeed, Congress decided last year to provide an additional 3,000 visas to resettle such Afghans - beyond the 7,183 issued since 2014, after years of delays.

Yet an infuriating bureaucratic wrangle in Washington threatens to block many of these Afghans from reaching America and could get some of them killed.

The problem has arisen because, when increasing the number of visa slots, Congress changed the rules to require that the applicants have worked for the U.S. government for at least two years, rather than one. It's hard to imagine why such a change was made, since accompanying American forces on patrols for one year - and being threatened with death by the Taliban as a consequence - is surely as deserving of a visa as doing it for two years.

But the story gets worse.

This new two-year requirement was intended by Congress to apply only to new applicants. Instead, lawyers at the State Department and Department of Homeland Security interpreted some phrasing of the new rule to mean it should be applied retroactively. As a result, as many as 3,000 Afghans who were well into the long, complex application process could be disqualified, even though many of them already have been waiting for years for final approval.

To understand how heartless this is, let me tell you the stories of two Afghan interpreters whose last hopes are being destroyed because of this bureaucratic maze.

Ali was a young Afghan policeman who interpreted for U.S. military forces for 16 months in the dangerous Zabul and Kandahar provinces.

"If we hadn't helped U.S. forces, how could they have talked to people?" he asked me in a phone interview last week. "We thought our country would get peaceful, but it got worse. The Taliban got more powerful, and the Americans were leaving, so many interpreters had to go into hiding."

Because he had gone out with U.S. Army patrols and gathered intelligence on the locations of improvised explosive devices and Taliban double agents, he was denounced by some locals as a "spy" and a "traitor."

Then the death threats started coming.

One day masked men went to the home of Ali's sister, while he was out. They asked for him by name, then burst into the house and stabbed his brother-in-law to death.

Ali, his sister, and her small children immediately pooled their savings and hired smugglers to transport them to neighboring Iran. But in the crush of people also escaping the Taliban, Ali and his sister were separated. Because she didn't have a cellphone, he has no idea what happened to her and her children.

Since Iran wasn't safe, Ali had to keep going until he reached Europe (he didn't want the country named), where he is living in a crowded refugee center and worried sick about his sister. Because he didn't have adequate documentation, he faces deportation and Taliban reprisals if he is sent home. His case is being handled by lawyers from the admirable New York City-based International Refugee Assistance Project (IRAP), and he has glowing recommendations from his former U.S. military supervisors. But if the State Department's lawyers don't revisit their interpretation of Congress' language, he is as good as dead.

Then there is "Dave," an interpreter who worked with U.S. Special Forces from 2003 to 2011, going out on patrols and gathering intelligence in some of the most dangerous Afghan regions. IRAP lawyers have half a dozen letters from his U.S. military bosses about his bravery, sacrifice, and extraordinary service. In hiding since 2013, Dave has received Taliban death threats by phone, and had two (unsuccessful) attacks on his home, where his wife and two young children live. He is taking medication for anxiety and finds it impossible to sleep.

The former interpreter has run out of savings, and sold most of his family's possessions, but can't find work because of his service with the U.S. military.

"Whenever I am hired," he told me by phone from Afghanistan, "as soon as they find out I was an interpreter, they fire me because they know the Taliban will target their company if I work for them."

Yet, despite his long service, Dave is blocked from getting a U.S. visa because of the new rules - and their retroactive application. One U.S. civilian contractor who hired him has folded, so he couldn't get an employment verification letter; the second contractor didn't accurately list all his dates of service, showing him as having worked just under two years. That sufficed when IRAP lawyers first submitted his visa application. But more than a year later - thanks to the bureaucrats - he got a rejection because he "lacked" two years of service.

This kind of bureaucratic betrayal of Afghans who helped Americans is not only shameful, it is nuts.

Some U.S. legislators are working on a bipartisan letter to clarify congressional intent that the two-year employment requirement apply only to new applicants. The State Department's deputy spokesman, Mark C. Toner, says, "We are aware of concerns over parts of the legislation and are working with Congress to address them."

Let's hope that's true - with quick results, because time is running short. The longer the delay, the greater the risk of death to these brave Afghans.

"We did a lot," Ali told me in a tone of desperation. "All the solders we worked with know how we helped them."

How America rewards - or betrays - that help speaks volumes about who we really are.