Putin's goal in Ukraine is to stretch the Ukrainian defenses as thin as possible, while cutting the country off from the sea and occupied Crimea and possibly driving all the way to Moldova, said the former Estonian commander in chief, retired Gen. Ants Laaneots.
"Putin's goal is to make the theater of operations as wide as possible. He knows that Ukraine has few reservists," said Laaneots on ERR radio.
The goal of the southern front launched this week - the first time entire Russian battalions have been overtly involved in combat in Ukraine - is to continue a long-range operation that could be seen as a pincer movement on a massive scale and to force Kyiv to capitulate, said Laaneots, who served as commander in chief from 2006 to 2011.
"If he is successful in taking away Ukraine's eastern, southeastern and southern oblasts, Ukraine will be enveloped. That means it is a matter of time before it has to surrender to Moscow. Putin is following this very plan."
Russia's action, however, was precipitated by Ukraine's increasing military strength.
"When Crimea was taken away, it was a total crisis. Ukraine only had about 5,000 battle ready soldiers. Now they have started forming a new armed forces and they have succeeded," resulting in gains against the separatists in Luhansk and around larger Donetsk, said Laaneots.
That prompted Putin to bring in two units, which Laaneots, who besides being a founder of the modern Estonian military is a senior Soviet army veteran, identifies as the 76th Guards Air Assault Division and 98th Guards Airborne Division.
Laaneots estimates 15,000 Russian soldiers have been involved in some way in eastern Ukraine. The change now is that entire armored battalions as opposed to smaller companies have entered Ukraine, he said.
He said the Russians were using T-72 tanks, some of them refitted - "far from being new tanks," and thus contrary to a report from the BBC. The Ukrainians are mainly using Ukrainian-made T-64s.