The Ukrainian parliament's vote this month to break off most forms of military and intelligence cooperation with Moscow over the conflict with Russian-backed rebels in eastern Ukraine threatens to upset an uneasy peace in Moldova's breakaway Transdniester region.
The Verkhovna Rada voted on May 21 to scrap a series of bilateral agreements on military cooperation with Russia, including a key provision that allows Moscow to send forces by land across Ukraine to the breakaway region.
William Hill, the former head of the OSCE Mission to Moldova and now a scholar at the Wilson Center, a nonpartisan research group based in the United States, says it's the first time Ukraine has formally abrogated its agreement with Russian soldiers, and the move could be a "serious step."
"It's never been tried over the long term since 1992," when a cease-fire deal was signed in Transdniester's separatist war, Hill says. "So we get into uncharted territory and will rapidly, could rapidly, get to a situation where one doesn't really know what to expect next."
The move effectively cuts off Russian access to the around 1,500 soldiers it maintains in Transdniester, a sliver of land that borders Ukraine -- but not Russia. The Russian deployment there is divided into an internationally mandated peacekeeping force of around 380 troops, with the rest being regular soldiers as part of its 14th Guards Army.
Russia remains Transdniester's major -- and practically only -- international ally after Moscow backed separatists in the 1992 conflict that ended with the tiny region, with a population of around 500,000, gaining de facto autonomy. Two decades of international efforts to mediate an end to the conflict have largely failed, though a fragile peace has held and relations between the province and the Moldovan capital, Chisinau, are workable.
Relations, however, between Chisinau and Moscow remain badly strained over Moldova's efforts to align itself more closely to the European Union and the country's attempts to block what it calls "pro-Russian propaganda" aired by Russian television stations accessible in Moldova. Moscow has retaliated by banning many Moldovan exports, including wine, which has hurt the Moldovan economy.
Ironically, Hill says, ties between Chisinau and Transdniester's nominal capital, Tiraspol, had been improving recently with the installation of Moldovan Prime Minister Chiril Gaburici. Hill says part of the credit goes to the negotiator for the Moldovan side, Victor Osipov, who has restarted several working groups that had been previously inactive.
So far, Russia's reaction to the Ukrainian parliamentary decision has been muted, though it's hard to know what is going on behind the scenes.
Russian Deputy Prime Minister Dmitry Rogozin, shortly after the decision, accused Ukraine of "betraying" its citizens living in Transdniester -- presumably referring to the fact that ethnic Ukrainians comprise around one-third of Transdniester's population. He said the move would not affect Russian military operations in Transdniester, though he didn't elaborate on how Russian soldiers would move in and out of the region.
One point of access for Russian soldiers traveling to Transdniester remains Chisinau's international airport and the short overland journey from there to Tiraspol.
Over the years, Moldova has largely permitted Russian officers and soldiers to transit the airport on their way to Transdniester, though in the past few months, Chisinau has periodically blocked and deported soldiers who were not clearly identified as international peacekeepers or who have failed to give sufficient advance notice.
The turnbacks have enraged Moscow. On May 26, the Russian Foreign Ministry said it was "particularly concerned" over "Russian peacekeepers" denied entry into Moldova. It said Moldova's action "seriously complicates" the mission to maintain peace in Transdniester.
IN PICTURES: Transdniester -- A Post-Soviet Relic In Europe
Hill says that Moldova has no formal obligation to allow Russian soldiers, even those operating as peacekeepers, to transit Moldovan territory to Transdniester. While the country is obliged to respect the decisions of a tripartite Joint Control Commission -- with Russia and Transdniester -- established by the 1992 cease-fire agreement, he says, Moldova can stop whomever it wants.
Chisinau has been particularly wary of Russia's intentions since Moscow's seizure of Crimea and the outbreak of the conflict in eastern Ukraine, which has killed more than 6,100 people since April 2014. It has also sparked fears that Russia and the rebels could seek to seize control of a huge swath of southern Ukraine up to the border with Moldova and Transdniester.
"Moldova has been restricting or very carefully looking at transit through their airport ever since the demonstrations in Odesa last year," Hill said, referring to a major southern Ukrainian port city not far from Moldova.
'Both Sides Fear Provocations'
At the time, he said, there were "widespread reports the Russians and the eastern Ukrainian rebels were trying to slip special forces through Transdniester into Odesa to seek to boost protest activities" in and around Odesa.
The only other option open to Russia would be by air. Tiraspol has a large enough airport to handle in-flights of Russian soldiers, though under the current circumstances Ukraine -- which calls the rebels terrorists and accuses Moscow of backing them with weapons and troops -- would be unlikely to grant Russia overflight rights.
Ion Leahu, a former member of the Joint Control Commission from Moldova, says in his view, this leaves Russia with two options: withdraw troops from Transdniester, with a corresponding change in the composition of the international peacekeeping force there; or negotiate a separate air corridor with Chisinau.
This latter option, he says, would prove difficult in practice. "The official Chisinau Airport would likely only ever agree to the possibility of moving employees, officers, and soldiers of the peacekeeping forces," he says. "For us, [the passage of soldiers of the] 14th Guards Army would be absolutely illegal. In the same way, using the Tiraspol Airport would be illegal, according to international norms."
Hill says it's difficult at this stage to predict the consequences, but that all sides would likely go to great lengths to avoid a resumption of hostilities.
"My observation is that nobody there, on either the Moldovan side or the Transdniester side, really wants to start fighting again," he says. "Both sides fear provocations -- the creation of incidents that might create pressure on the other side."
Whatever happens, one casualty of the Ukrainian decision is likely to be Transdniester's struggling economy -- both the legitimate trade in steel, manufactured goods, and textiles, and the thriving illicit trade in contraband cigarettes, booze, and -- recently -- frozen chicken parts.
Any impact on the black market, however, would depend on the willingness of officials in Ukraine, Moldova, and Romania to enforce their own customs laws.
"The bottom line, the short answer, is that it's not going to be good for the Transdniestran economy," Hill says. "A region which is already in deep economic trouble can only look forward to harder times."