Vladimir Putin has insisted that there are no Russian troops in eastern Ukraine - just like he insisted there  were no Russian troops in Crimea until he admitted it last week.

Now, the New York Times reports there are photos that clearly show known Russian military and intelligence people mixed in with pro-Russian militias, fomenting strife in Eastern Ukraine.

For two weeks, the mysteriously well-armed, professional gunmen known as “green men” have seized Ukrainian government sites in town after town, igniting a brush fire of separatist unrest across eastern Ukraine. Strenuous denials from the Kremlin have closely followed each accusation by Ukrainian officials that the world was witnessing a stealthy invasion by Russian forces.

Now, photographs and descriptions from eastern Ukraine endorsed by the Obama administration on Sunday suggest that many of the green men are indeed Russian military and intelligence forces — equipped in the same fashion as Russian special operations troops involved in annexing the Crimea region in February. Some of the men photographed in Ukraine have been identified in other photos clearly taken among Russian troops in other settings.

And Ukraine’s state security service has identified one Russian reported to be active among the green men as Igor Ivanovich Strelkov, a Russian military intelligence operative in his mid- to late 50s. He is said to have a long résumé of undercover service with the Main Intelligence Directorate of the Russian general staff, most recently in Crimea in February and March and now in and around the eastern Ukrainian city of Slovyansk.

“There has been broad unity in the international community about the connection between Russia and some of the armed militants in eastern Ukraine, and the photos presented by the Ukrainians last week only further confirm this, which is why U.S. officials have continued to make that case,” Jen Psaki, the State Department spokeswoman, said Sunday.

The question of Russia’s role in eastern Ukraine has a critical bearing on the agreement reached Thursday in Geneva among Russian, Ukrainian, American and European diplomats to ease the crisis. American officials have said that Russia would be held responsible for ensuring that the Ukrainian government buildings were vacated, and that it could face new sanctions if the terms were not met.

This CBS video reports on Ukraine's case:

I suppose it's possible this is a case of mistaken identity, but Russia has invented a new kind of warfare that relies on subterfuge like this:

John R. Schindler, a former National Security Agency counterintelligence officer who now teaches at the Naval War College, calls it “special war”: “an amalgam of espionage, subversion, even forms of terrorism to attain political ends without actually going to war in any conventional sense.”

And one country, Mr. Schindler noted in an article last year in which he coined the term, that particularly excels at special war is Russia, which carried out its first post-Soviet war to regain control of rebellious Chechnya back in 1994 by sending in a column of armored vehicles filled with Russian soldiers masquerading as pro-Moscow Chechens.

Russia’s flair for “maskirovka” — disguised warfare — has become even more evident under Mr. Putin, a former K.G.B. officer whose closest advisers are mostly from that same Soviet intelligence agency.

The last thing Putin is worrying about is his credibility. He cares about winning. And that, he is doing quite handily.