Officer Mohammad Aref spends his days directing swarms of traffic around one of Kabul's busiest intersections, where old cars spew exhaust and lurch between pedestrians.
But he is thrilled to have the job because, during the Taliban era, he was fired from his position on the police force. The reason, he says: He spoke the wrong language.
"I was dismissed from my job because I speak Dari, not Pashto," says Mr. Aref, abandoning his traffic circle for a moment.
These are the oft-overlooked politics of language in Afghanistan, a subtext that usually takes a backseat to the warlords and battlefields.
Whether Aref's policing skills were actually lacking is hard to ascertain. But it's clear that many here found themselves on the outs with the Taliban regime in part
because they couldn't speak its language, Pashto. The tongue predominates in cities such as Jalalabad and Kandahar and is characteristic of ethnic Pashtuns, who make up about 40 percent of the Afghan population.
Now, the tables are turning again. The lingua franca of the interim government is Dari, an Afghan dialect of Farsi, the language of Iran. For example, an important military agreement governing the mandate of the 4,500 foreign peacekeepers who are to help bring security to Afghanistan comes in Dari and English versions only. Even though Hamid Karzai, the leader of the interim government, is an ethnic Pashtun, he usually speaks in an erudite Dari, but offered some words of Pashto in his inaugural speech as a gesture.
"If he had not done that, then the people in Kandahar would say, 'You're a Pashtun, why are you speaking in Dari?' And they'd be angry at him," says one translator who, like many in Kabul, now speaks both languages.
Some here worry that the predominance of Dari-speakers in the new government will create resentment among Pashtuns, who feel underrepresented.
Meanwhile, the interim administration announced Wednesday that it was beginning to enforce a plan to disarm Kabul, awash with firearms after 23 years of war.
"The government decided yesterday to implement the security agreement as it was agreed in Bonn," Interior Minister Yunis Qanooni said Wednesday, referring to the transition of power accord reached at UN-sponsored talks in December.
Disarming is only one aspect of bringing order. Understanding the Pashtun culture and language provides a window into the ties that bind the Pashtun of southern Afghanistan to their tribal brethren in Pakistan - and explains why there may be little incentive for Pakistani Pashtun to turn in fleeing members of the Taliban or Al Qaeda.
"The authorities in power have an effect on people's behavior. During the Taliban regime, the people in their offices tried to speak Pashto," says Bakhtmir Wazir, an associate professor of Pashto at Kabul University. When the Taliban fell soon after the US airstrikes began in October, he says, "the people suddenly switched and spoke Dari again."
It is not the first time that Kabul's vernacular has shifted camps. When Professor Waziri was a student, he recalls, a Pashtun-led government was in power and the university's Pashto classes were oversubscribed.
Dari and Pashto are both Indo-European languages. Dari speakers describe their language as richer, with a long history of literature. Most of the nation's scientific books are in Dari, and its speakers see cultural and linguistic links to Farsi or Persian.
Pashto, on the other hand, does not claim as deep a literary tradition because it had fewer outside influences: Most of its speakers lived on remote mountaintops and valleys, and prided themselves on conservatism. One poem from the 9th century, "Wearana," is an epic verse about pride and the power of defending one's home, Waziri says.
Those, in fact, are key themes of the Pashtunwali, or the Pashtun tribal code, the law of the land for many in Afghanistan. It governs disputes and relations between clans, and reveres hospitality, courage, and integrity. More often than not, it is what defines the Pashtun - and can override both existing civil law and even sharia, or Islamic law.
"We have an expression," Waziri says half-jokingly. "Pashtuns believe in half the Koran."
Another professor here, Dr. Mukammil, says that many Pashtun have been purists - a characteristic with which the Taliban went overboard.
"We respect purity of culture, so our people didn't want other cultures to influence it," says Mukammil. "But it doesn't mean Pashtuns are against education and culture. In any age, a Pashtun has in one arm a sword, and the other, a pen."
Both professors come from areas that were split by the British a century ago. In 1893, the British imposed the Durand Line, a boundary between Afghanistan and what was then British India, dividing Afghanistan's Pashto-speaking tribes from the Pashtun of northwest Pakistan. Divided by this border, half of Mukammil's family and property is in Pakistan, he says. Waziri crosses over regularly to attend weddings, and sends his son to school in Peshawar. The only difference linguistically is that their relatives there speak Pashto with some words of English and Urdu - the main language of Pakistan.
With this is mind, observers say, it is unlikely Pakistanis in these areas will turn in fleeing members of the Taliban who are fellow Pashtuns.
To be sure, not everything here boils down to Dari versus Pashto. A variety of Turkic languages are also spoken in Afghanistan. But it is the arm-wrestle between Dari and Pashto which is most strongly felt in the political arena.
"It is important that members of this government are from different ethnicities," says Waziri. "This is a war situation.... In the future, the leaders will make some better decisions on the makeup of the cabinet. Right now, the people are thirsty for peace."