It is as predictable as snow in a Russian winter. When Moscow has a tussle with one of its neighbors, Russian health officials suddenly discover something wrong with that country's exports.
This time, it is Ukraine, which is locked in talks with Moscow over energy prices and other contentious issues.
So it was predictable that senior Russian health inspector Gennady Onischenko would -- as he did this week -- announce that there has been "a marked deterioration" in the quality of Ukrainian cheese.
The announcement seemed to be a prelude to a ban, just as Moscow banned the import of Georgian mineral water in 2006, Belarusian dairy products in 2009, and Moldovan wine in 2010.
Ukrainian economist Ihor Burakovskiy told RFE/RL's Ukrainian Service that the move is clearly tied to larger issues between Moscow and Kyiv.
"Ukraine consistently refuses to join a Customs Union [with Russia, Belarus, and Kazakhstan]," he said. "Ukraine consistently rejects deeper integration in relation to gas. Therefore, one can view the latest statements as an echo of these problems."
But later this year, after 19 years of trying, Russia is expected to enter the World Trade Organization (WTO). When that happens -- and the Russian Duma is expected to ratify the agreements within months -- Moscow's health officials will still be able to ban such imports, says Stephen Woolcock from the International Relations Department of the London School of Economics.
But, he adds, they will have to apply uniform standards to all trade partners and provide scientific documentation to justify their action.
Woolcock says such matters are covered by the WTO's Sanitary and Phytosanitary Agreement (SPS). In addition, the SPS allows member countries to introduce temporary bans while such scientific evidence is gathered. He notes that the agreements do not place a time limit on such "temporary" bans.
In addition, WTO rules give recourse to countries targeted by such trade actions through a dispute-settlement procedure.
"If [such a procedure] found against Russia, then Russia would have to reverse the ban," says Wollcock. "Or, alternatively, pay compensation, as it is called, which means normally that Ukraine would impose compensatory restrictions on Russian exports. But this whole process would take a long time."
In addition, the WTO keeps an eye on trade policies and could pressure Moscow if it was found to be imposing politically motivated trade sanctions.
"There is regular monitoring of trade policy under what is called the Trade Policy Review Mechanism," Woolcock says. "So, if there were a pattern of the use of these sorts of measures, then other WTO members could challenge Russia in this process. But that is more peer pressure than a specific legal sanction. Any legal sanction, obviously, has to be based on an individual case."
RFE/RL's Ukrainian and Russian services contributed to this report