“The radical reconstruction of everything is required, so these problems are multiplying,” said Vladimir P. Kazarin, 66, a philology professor at Taurida National University. (The university’s name, which derives from Greek history, is scheduled to be changed.) “It will take two or three years for all this chaos to be worked out, yet we have to keep on living.”

On a deeper level, some Crimeans struggle with fundamental questions about their identity, a far more tangled process than merely changing passports.

“I cannot say to myself, ‘O.K., now I will stop loving Ukraine and I will love Russia,’ ” said Natalia Ishchenko, another Taurida professor with roots in both countries. “I feel like my heart is broken in two parts. It is really difficult psychologically.”

The Crimean government dismisses any doubts or even complaints.

“Nonsense!” said Yelena Yurchenko, the minister for tourism and resorts and the daughter of a Soviet admiral who retired in Crimea. These “are small issues that can be resolved as they appear,” she said, adding, “It might result in certain tensions for the lazy people who do not want to make progress.”

Legions of Russian officials have descended on Crimea to teach the local people how to become Russian. In tourism alone, Ms. Yurchenko said, Crimea needed advice about Russian law, marketing, health care and news media.

“Can you imagine how many people need to come to work here for just that one sector?” she said in an interview, explaining why even her ministry could not help anyone find a hotel room in Simferopol, the Crimean capital. “We also have transportation, economy, construction, medicine, culture and many other things.”

Other changes in national identity elsewhere, like the “velvet divorce” of the Czech Republic and Slovakia in 1993, happened with more advance planning. Crimeans feel as if they went through the entire reverse process in 1991, when Ukraine left the Soviet Union, which had transferred the peninsula to Ukraine from Russia in 1954. Confused? So are they.