If Vladimir Putin's ends remain mysterious, so do the means.

Putin is allocating unprecedented amounts of secret funds to accelerate Russia's largest military buildup since the Cold War, according to data compiled by Bloomberg. The part of the federal budget that is so-called black — authorized but not itemized — has doubled since 2010 to 21 percent and now totals 3.2 trillion rubles ($60 billion), the Gaidar Institute, an independent think tank in Moscow, estimates.

Stung by sanctions over Ukraine and oil's plunge, Putin is turning to defense spending to revive a shrinking economy. The outlays on new tanks, missiles and uniforms highlight the growing militarization that is swelling the deficit and crowding out services such as health care. Thousands of army conscripts will be moved into commercial enterprises for the first time to aid in the rearmament effort.