When the commander of NATO forces in Europe said Sunday that he was worried about Russian troops moving across Ukraine to Transnistria, he was talking about a sliver of land that has existed largely outside the international system and outside the law for 22 years.

U.S. Air Force Gen. Philip M. Breedlove was voicing fears that the small country of Moldova will very soon become Europe’s next crisis point.

How Transnistria was formed

Separatists who had already come to power in Transnistria more than a year earlier took advantage of the collapse of the Soviet Union in 1991 to break away from Moldova. Transnistria has maintained itself as a Russian-speaking ­enclave ever since.

(The Washington Post)

Many ethnic Russians and Ukrainians lived primarily in the more industrial eastern parts of the former Soviet republic, and they wanted no part of the new Moldova. Moldovans are closely related to their neighbors, the Romanians.

Transnistria refers to the land beyond (or east of) the Dniester River.

The region is often lumped with other corners of the old Soviet Union that broke away from newly emerging nations into a kind of unrecognized limbo. There’s Nagorno-Karabakh, an ethnic Armenian part of Azerbaijan, and Abkhazia and South Ossetia, which have separated themselves from Georgia with Russian help.

[See more about the world’s “gray areas”]

How Russia is involved

After brief and inconclusive fighting broke out, the Russian army imposed a truce on both sides in 1992. Russian Lt. Gen. Alexander Lebed, a profane and charismatic officer, had little use for either the Moldovans or the Transnistrians, who began to devote sectors of their economy to human trafficking, drug running and arms smuggling. But he successfully separated the two warring parties, and they’ve stayed that way ever since.

Lebed played a key role in bringing Russia’s first Chechen war to a peaceful end in 1996. Highly popular, he went into politics and was killed in a 2002 helicopter crash that some thought was suspicious.

A Russian army base in Trans­nistria, with 1,200 soldiers, has helped ensure the region’s invulnerability.

Russian President Vladimir Putin said last week that his country reserves the right to stand up for ethnic Russians living outside its borders. His remarks came in a speech about Crimea, but that protection could presumably ­extend to Russians in Moldova as well as in Kazakhstan, Estonia, Latvia and Lithuania.

What it’s like now

Transnistria has a population of about half a million, down 10 percent in the past 10 years. At 1,600 square miles, it is slightly smaller than Cook County, Ill. Its flag still features the Soviet hammer and sickle.

Largely because it could capitalize on its location in Eastern Europe, Transnistria in the 1990s became a hotbed of international criminal activity. That appears to have receded more recently.

Moldova is one of Europe’s poorest countries and is the world’s leader in per-capita alcohol consumption.

Where it might be headed

Moldova has joined with Georgia in agreeing to sign up for a formal trade deal with the European Union — exactly the same deal that Ukraine was headed for last fall until Moscow persuaded it to change course, sparking protests that led to the current situation.

Some Transnistrians have been agitating to join Russia. In a 2006 referendum, 96 percent of voters opted for accession, but Moscow turned them down. Russia has been taking part in a 21-year-old mission by the Organization for Security and Cooperation in Europe to settle the status of the region.

Some elements in the enclave would prefer that Transnistria retain its shadowy existence.

A note on pronunciation

and spelling

Webster’s New World College Dictionary gives the pronunciation of Transnistria as trans-NEES-tree-uh. It’s also spelled Transdniestria or Trans-Dniester.

The river is spelled Dniester or Dnestr.