Putin's self-driving tanks
Now it appears that three T-72 tanks have magically crossed from Russian into eastern Ukraine under their own power, somewhat like an American drone aircraft or a Google self-driving car. In this, they are remarkably like the Ukrainian "separatists" who dress like Russian soldiers, act like Russian soldiers, and fight like Russian soldiers
The separatist tanks will no doubt be passed off as indigenous, and the weasels in Berlin, Paris, and Washington will no doubt seize upon that explanation as an excuse not to do anything about them. All Ukrainian tanks are of Russian manufacture and/or design, so it won't take much to pass them off as weapons that Kiev has somehow managed to mislay.
There's video of the incursion on Britain's Daily Mail.