NATO hesitation to give Ukraine weapons is one aspect of the snagging counteroffensive.
The timing prevented Ukraine from taking full advantage of Russia's weaknesses, analysts said.
The US and NATO have provided Ukraine with billions of dollars of aid, including Western weapons, air defense systems, tanks, artillery, and combat vehicles.
Since the beginning of the war, Russian President Vladimir Putin has threatened the use of nuclear weapons in Ukraine.
"There's no world in which Putin can drop one tactical nuke and then that fundamentally changes the outset of the war," Barros added.
Persons:
—, George Barros, Mykhailo Podolyak, Kyiv's, Joe Biden's, Barros, it's, could've, Biden, Vladimir Putin, Seth G, Jones, Harold Brown, Putin
Organizations:
Service, Ukraine —, Institute for, Kyiv, Russian, Institute, NATO, Abrams, Leopard, AP, Western, Transnational, Center for Strategic, International Studies
Locations:
Ukraine, Russia, Kyiv, Western, Russian, Belarus