Lavrov’s statement is essentially correct. I don’t know about “valiant” but they killed far more nazis than anyone else until the Allied invasion of North Africa and Italy in 1943. The fact that Stalin had signed a nonaggression pact with Hitler before hitlers invasion of Poland, then scooped up chunks of Poland and tried to seize Finland and the Baltic countries before hitler turned on him is often forgotten. Stalin also had no problem feeding soviet troops and civilians into the nazi grinder without regret. However it was proven to be necessary to kill nazis, but valiant had nothing to do with it.
Agreed with your post until this... nothing was "proven". It worked, but many other methods could have worked as well... meaning it wasn't "necessary"... and almost certainly with fewer casualties... which would qualify as "a better solution" in the minds of just about any rational human being. Stalin refraining from murdering every competent general would've been a mighty good start.
The perseverance of the Russian People during the siege of Leningrad was definitely valiant.
In fact, the entire performance of the people of the USSR in World War II was valiant.
It is also true that the Soviets could not have defeated the Nazis without the shipment of enormous quantities of ordinance from the USA to the USSR. This ordinance--in fact the enormous ordinance produced by the USA, essential to winning the war--was entirely the result of the American Free Market--i.e. capitalism--and the freedoms whose protection is guaranteed in the U.S. Constitution.
US wealth--produced by the Free Market--won World War I, World War II, and the Cold War.
A friend who immigrated to the USA from Iran (a Christian, by the way) told me that during World War II he watched endless convoys passing through Iran from America headed for the USSR. He marveled as the enormity of it all. Everyone who witnessed these caravans was astonished--astonished at the wealth of a nation that could ship so much to the USSR--wealth produced by freedom, for the Free Market--i.e. capitalism--is, in fact, freedom. It was then that he began to dream of coming to America.