Experts say the dispute is unlikely to affect downstream customers in Europe – which depends on Russia for more than a quarter of its gas – as previous spats with Russia's neighbor Ukraine have frequently done. Belarussian pipelines carry just 20 percent of Russian exports to Europe and demand is much lower now due to warm summer temperatures.
But the shutdown does reflect ongoing Russian willingness to use energy as a tool of foreign policy, experts say.
Moscow has reportedly been losing patience with Belarussian President Alexander Lukashenko, who talks a strong pro-Russian game but actually pursues an independent course that increasingly conflicts with the Kremlin's wishes.
In recent months, Mr. Lukashenko has dug in his heels against joining a Belarus-Kazakhstan-Russia customs union being championed by Russian Prime Minister Vladimir Putin, has demanded duty-free Russian oil as the price of further cooperation, and has given refuge to ousted Kyrgyzstan leader Kurmanbek Bakiyev, some say against the Kremlin's wishes.
"This gas cutoff is just another stage of the general crisis of relations between Russia and Belarus, and in particular Lukashenko's refusal to sign the customs union agreement with Putin," says Yaroslav Romanchuk, an analyst with Strategia, one of the few independent political think tanks in the Belarussian capital of Minsk. "There will soon be a presidential election campaign in Belarus, and it seems like Putin and [Russian President Dmitry] Medvedev have given up all hope of coming to terms with Lukashenko."
On Monday, Mr. Medvedev ordered the Kremlin-run gas monopoly, Gazprom, to slash gas deliveries by 15 percent each day until the amount reaches 85 percent of Russian supplies to Belarus's state-run economy, or an amount equal to the $192-million debt claimed by Moscow.
Lukashenko at first offered to cover the debt with farm products and machinery, a suggestion that was rejected out of hand by Medvedev. "Gazprom cannot take pies, butter, cheese, or pancakes or any other form of payment [except cash]. Our Belarusian partners must understand this," Medvedev said.
By late Monday, Belarus' deputy prime minister Vladimir Semashko said the country would try to pay the debt within two weeks, even if it has to borrow the money. But Gazprom indicated that it would keep up the pressure, and re-route European gas supplies through Ukrainian pipelines for the duration of the dispute.
Analysts say the Ukrainian example clearly illustrates how the Kremlin uses gas to coerce its neighbors. While pro-Western former Ukrainian President Viktor Yushchenko was in charge, Russia and Ukraine went through repeated annual "gas wars," and Russia jacked up Ukraine's energy prices to the same rates paid by Western European customers.
But since a Moscow-friendly leader, Viktor Yanukovich, was elected in February, Russia has made a series of sweetheart deals with Kiev, including granting a 30 percent discount on gas prices in return for Russia's continued use of a naval base on the Crimean peninsula.
"Russia found it easy to lower Ukraine's gas bill, once it saw political reasons to do so," says Alexei Makarkin, deputy director of the independent Center of Political Technologies in Moscow. "This dispute with Belarus is all about negotiations over the customs union project, and other political issues. Moscow has not been happy with Lukashenko's flirting with the West, or his refusal to grant diplomatic recognition to [the Russian-sponsored Georgian breakaway statelets of] South Ossetia and Abkhazia," he says.
Lukashenko, a former collective farm director who has often been slammed as "Europe's last dictator," was freely elected in 1994 but has since held on to power by suppressing opposition and allegedly rigging elections. He recently told journalists that he will run for a fourth term of office, in polls to be held early next year.