Note to myself
Guardian 17 December 2015: Putin admits Russian military presence in Ukraine for first time
Reuters 17 December 2015: Russia's Putin lashes Turkey, says Russian forces were in Ukraine
Compare with summary in Power and Law in International Society, page 155: "Similarly, Russia went to great length in its illegal annexation of Crimea in 2014 to argue that the “green men” taking control over various buildings were “local self-defense forces” and not Russian troops,132 contradicted by various international observers and later by president Putin himself.133"
132 ‘Russia says cannot order Crimean 'self-defense' units back to base’ Reuters (5 March 2014)