The Soviet Union lasted less than that, but the legacy of this most recent empire is still apparent, though not in the form of architectural monuments. What lingers here are some of the political habits bequeathed by the Soviets, who ruled Central Asia with an iron fist from the 1920s until 1991.

Nowhere is this more obvious than at border posts between the two countries, where uniformed officials rifle through suitcases, pulling out suspicious objects like hair curlers, leafing through English-language novels and barking out contradictory instructions on how to fill out multiple declarations.

The procedure can take hours, which is hard on tourists but even more painful for local citizens trying to visit relatives who live in what is now another country. In Turkmenistan, most people are required to obtain exit visas to leave the country, as was the case in the Soviet Union; families are given a visa for seven days to attend funerals in Uzbekistan, two of which are spent crossing the border. Uzbekistan’s travel rules are less restrictive.

Like the Soviet Union in the years before Mikhail Gorbachev’s perestroika, both Uzbekistan and Turkmenistan are living under regimes that resolutely and brutally resist change. President Islam Karimov of Uzbekistan has been in power for 26 years, counting two years as the country’s Communist Party boss. He was re-elected last March, Soviet-style, with more than 90 percent of the vote.

Turkmenistan’s first president, Saparmurat Niyazov, made the same smooth transition from Communist Party first secretary to president, keeping a tight lid on his country of 5.1 million while cultivating a bizarre cult of personality. Before he died in 2006, he ordered the construction of his own mausoleum, next to a giant mosque, now guarded by the same kind of goose-stepping soldiers who keep watch over Lenin’s tomb on Red Square in Moscow.