The article provides an explanation of how energy resources become instruments in Russia’s foreign policy towards countries-consumers at the same time indicating elements determining the efficiency of energy instruments to reach Russia’s foreign policy goals. The article argues that Russia expanded its state power in energy sector through direct and indirect mobilisation. There are two types of energy instruments - sway and compel. The effectiveness of energy instruments depends on barriers country-consumer has. Instruments may have positive targeted and foreseen as well untargeted and unforeseen negative consequences for Russia and countries-consumers in Post-Soviet space especially focusing on Belarus and Ukraine.