On Tuesday, several days after Russian self-propelled artillery moved into eastern Ukraine in what was clearly a hostile invasion that Vladimir Putin insists is not occurring, someone took a video of some very heavy tanks crashing around an eastern Ukrainian town near the rebel-held city of Luhansk. While they look suspiciously like Russian tanks sent as part of the invasion, Moscow and the pro-Russia rebels have all insisted that any heavy equipment was stolen from or abandoned by the Ukrainian military.

But now military analysts have taken a look at the video and say that at least one of the tanks could only come from the Russian military, apparently settling the issue of whether these are in fact Russian military forces.

Joseph Dempsey, an analyst with the International Institute for Strategic Studies, told the BBC that one of the tanks is something called a T-72BM, a modern variant identifiable by its special "Kontakt-5 Explosive Reactive" armor, and one that Russia has not exported but uses heavily in its own military. That is a new development, and one that suggests not just that Russia is invading, but being increasingly brazen about it.

Dempsey told the BBC, "The Soviet-era tanks operated by the separatists have until now represented those that could have been potentially acquired internally within Ukraine, providing a degree of plausible deniability to any suspected third-party supplier." That degree of plausible deniability is now gone.