Turmoil in Global Wheat Prices

Environmental instability in Russia is proving to have a direct impact global markets. The massive fires and droughts of this absurdly hot summer diminished Russian what supply by about a 1/3. This dramatically decreased supply (seeing as Russia is the one of the world's largest wheat producers) has nearly doubled the price of wheat worldwide. This prompted nationalist policies in Russia, further reducing supply to developing nations which are highly dependent on Russian production. Riots in Mozambique point to the desperation caused by the price hike. Is Russia justified in pursuing nationalist policies in the face of what could be an international food crisis?