The current passport restriction, then, was initially designed to weed out people who might do this sort of thing again. But now they seem to have extended it to all Tibetans in Tibet, using the excuse that their passports -- even if they are valid and even if they're about to travel somewhere -- have to be replaced by new-issue electronic passports. And the new rules say that any Tibetan, before getting a new passport, if indeed they ever get one, must make a written declaration not to do anything while abroad that might threaten China's national security, and must be visited by the police and interviewed once he or she returns to see if they kept this undertaking. Though there have been many kinds of unprecedented restrictions applied in many spheres of Tibetan life since the protests of 2008, this is one of the more surprising ones.

What are some of the other restrictions placed on the Tibetans since 2008?

There have been many. These include the Chinese government putting Communist Party cadres in every monastery, requiring every monastery to display pictures of Chairman Mao Zedong, putting troops on every corner of the Tibetan quarter in Lhasa, limiting foreign visitors to guided groups, having to give their names before photocopying, not being allowed to enter Lhasa without a police guarantee if they're from another Tibetan area, and many more.

Are the Tibetans being singled out on this passport issue? Are Chinese citizens living in Tibet similarly affected?

There was some word that the passport withdrawal would be done to Han Chinese citizens too, under the name of adapting to new electronic/bio data passports. But thus far I hear that there are Chinese people in Tibet whose passports were not taken, and others say that even if Chinese ones were taken, they get them back quickly. Tibetans so far have not reported any being returned, as far as we know.

Will this crackdown on passports affect very many people? What is China's motivation for enacting this restriction?

China's main policy in Tibet for the last 20 years or so has to been to win people over by pouring huge amounts of money into the area, so quite a lot of Tibetans -- especially businessmen and retirees -- now constitute an urban middle class that travels to Nepal or India as often as possible. For many years, no Tibetans could get passports unless they were officials, but in the last decade or so this was relaxed for these new middle class urbanites, who are mostly former minor officials themselves or relatives of such officials and so were probably considered slightly less of a risk. What has changed, following the protests of 2008, is that these people are no longer trusted. This group, by the way, constitutes quite a few people: I would guess that they number in the tens of thousands at least, perhaps many more, and they are a significant, influential sector of the population.

Do you, more generally, foresee any change in Beijing's policy toward Tibetans under the new Xi Jinping administration?

Yes, I'm expecting the new leaders to try to take a softer approach, since the current policy damages China's image abroad and its stability at home, but there will be heavy internal resistance to it from bureaucrats and others invested in the hard-line approach. As a result any change is likely to be largely symbolic and almost imperceptible to outsiders.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.