Belarus has been increasing its military cooperation with Russia during the period of the crisis in Ukraine, but analysts argue that is as much as a way to keep Moscow at arm's length as a desire for closer ties.

Earlier this month, Russia sent six Su-27 fighter jets to Belarus's Babruisk airfield, which Belarusian President Alexander Lukashenko said was prompted by the U.S. sending its own fighter jets to neighboring Poland and Lithuania. “We reacted calmly until large-scale exercises began ... in Poland,” Lukashenko said. “There is a clear escalation of the situation near our borders.”

Meanwhile, however, Belarus's government has been noticeably reluctant to toe Moscow's line on Russian policy in Ukraine. Its foreign ministry has not endorsed the Crimean annexation, unlike many of its fellow Collective Security Treaty Organization members like Armenia, Kazakhstan, and Kyrgyzstan.

As the Belarus Security Blog argued, Belarus considers its military to be a low priority. "In this case, official Minsk decided to demonstrate its loyalty on defense issues in order to neutralize the effect from refusing to follow Russian policy," a recent post said.

Ryhor Astapenia, the editor of Belarusian magazine Idea, argued the same point. "For many outsiders, Lukashenka looks like the Kremlin’s vassal and the Belarusian army like a division of Russia's armed forces. However, the Belarusian authorities have refused to support the actions of Russia in the Crimea and Belarusian troops continue to remain within the country’s borders," he wrote. "It seems that regime wants to testify to its loyalty to the Kremlin after its recent refusal to support Russia in the Crimean conflict. Belarus, it cannot be forgotten, has a strong desire to acquire new military equipment as well."

The deployment took place against the backdrop of negotiations between Moscow and Minsk over the establishment of a Russian air base in Belarus. BSB suggests that the Su-27 deployment could be the first step in establishing the base (the location of which seems not to have been formally announced). But the establishment of the base seems to be dragged out, according to another analysis in Belarus Digest, citing continuing uncertainty over the delivery of S-300PS air defense systems from Russia to Belarus.