Fyodor Dostoevsky’s mystical idea of the suffering Slavs uniting and seeking out other sufferers was shared by many Russians, including the Russian Orthodox clergy. There would be a reign of righteousness once Moscow had become the Third Rome. It would be the dawn of the Millennium.  (Background: Periodic Pan-Slavism, Ersjdamoo’s Blog entry of April 20, 2014.)
A different version of Millenarianism – the belief by a religious, social, or political group or movement in a coming major transformation of society, after which all things will be changed  – has been held by the Anglo-American Establishment. It desires to federate all the English-speaking peoples and to bring the world under its control.  This is called “New World Order.”
A key book for Pan-Slavism, Russia and Europe, by Nicholas Danilevsky, was published in 1869. This book was the chief manifesto of the Pan-Slavs. Danilevsky also wrote a two-volume book critical of Darwinism. Inspired by the zoological ideas of Georges Cuvier, Danilevsky enumerated ten “cultural-historical types or distinctive civilizations.” One of these, the Germano-Romanic civilization, had passed its peak, and the time of a Slavic civilization had come. Danilevsky called upon all Slavs, be they Russian, Czech, Serb, Croat, or others, to elevate the idea of Slavdom. “Slavophilism had been finally secularized, and became Pan-Slavism.” 
Russia has long regarded itself as the protector of Orthodox Christians. There is also, as mentioned above, an historical impulse to protect all Slavs. 
In 1853, Tsar Nicholas I, in his role of protector of Orthodox Christians, occupied the principalities of Moldavia and Wallachia. 
In its role of protecting the Slavs, Russia, in 1812, took Bessarabia from the Ottoman Empire, thereby giving the Serbs a chance for local self-government. The Serb state was established in 1830. Turkey (then the Ottoman Empire) made war on Serbia, but then Russia, as protector of the Slavs, came to its rescue. The Turks were forced to accept the Treaty of San Stefano in 1877. That treaty was rewritten in 1878 and Serbia’s independence was established. 
There is thus precedent for Russia to intervene to protect Slavs and Orthodox Christians.
But why didn’t Russia intervene to protect Serbs during the Kosovo War, part of the Yugoslav Wars of 1991 – 1999? The answer to this could be Boris Yeltsin. He was Russia’s President from 1991 to 1999, coincident to the Yugoslav Wars. Yeltsin presided during a time of great upheaval in Russia, consequent to the collapse of the Soviet Union. Was Yeltsin drinking heavily on the job during the Serbian crisis? Opinions vary as to whether Boris Yeltsin was an alcoholic: Bill Clinton alleged that in 1995, when Yeltsin was visiting Washington, DC, the Russian President was found on Pennsylvania Avenue, drunk, in his underwear and trying to hail a cab in order to find pizza; however according to former Deputy Prime Minister of Russia Boris Nemtsov, bizarre behavior of Yeltsin resulted from “strong drugs” given to him by Kremlin doctors, which were incompatible even with a small amount of alcohol. 
On December 31, 1999, Yeltsin made a surprise announcement of his resignation. The new Russian President would be Vladimir Putin. Putin now lays claim to Russia’s venerable precedent of protector of Slavs and Orthodox Christians. Opposing Putin are the New World Order gang. They want to encircle and eventually strangle Russia. (You can’t have a New World Order while Russia stands in the way.) But Vladimir Putin is no Boris Yeltsin, and so tensions now rise between the Anglo-American Establishment and the Pan-Slavs.
——- Sources ——-
 Tragedy and Hope, by Carroll Quigley. New York: Macmillan, 1966
 The West in Russia and China: Russia, 1472-1917, by Donald Treadgold. Westview Pr (Short Disc) (January 1986)
 “Boris Yeltsin”, Wikipedia, April 21, 2014