In the Donetsk region of eastern Ukraine, the Supreme Soviet, as its separatist legislature is known, is nationalizing coal mines and reviving collective farms. At parades, people wave hammer-and-sickle flags; school officials talk of revising the curriculum to celebrate the triumphs of the Soviet Union.

There is now a secret police force called the M.G.B., reminiscent of the K.G.B. Some rebels call it, only half-jokingly, the N.K.V.D., the notorious Stalin-era secret police force.

The unrecognized separatist mini-states in eastern Ukraine, the Donetsk and Luhansk People’s Republics, were rescued from a near-death experience last month, when a Russian military incursion routed the Ukrainian Army as it appeared close to completing a campaign to wipe the rebels out. A cease-fire that preserved the regions’ semiautonomous status was signed on Sept. 5.

In the relative lull in fighting since, rebel leaders have busily set about building the sort of neo-Soviet states that have cropped up in other pro-Russian enclaves in the former Soviet Union: in Abkhazia and South Ossetia, both on the border between Russia and Georgia, and in Transnistria. If a stalemate similar to these “frozen conflicts” were to last in eastern Ukraine, it could make eventual reintegration with the rest of the country difficult, if not impossible.