(CNSNews.com) - "This is about freedom," President Joe Biden said on Wednesday, as he reaffirmed the "unity" of NATO and announced that the United States will send 31 Abrams tanks to Ukraine, a contribution that Germany demanded before sending its own Leopard 2 tanks to Ukraine.
"Ukrainians are fighting an age-old battle against aggression and domination. It’s a battle Americans have fought proudly time and again, and it’s a battle we’re going to make sure the Ukrainians are well equipped to fight as well.
"This is about freedom. Freedom for Ukraine, freedom everywhere. It’s about the kind of world we want to live in and the world we want to leave our children," Biden said.
He said Defense Secretary Austin recommended the delivery of tanks, "because it will enhance the Ukraine’s capacity to defend its territory and achieve its strategic objectives."
"The Abrams tanks are the most capable tanks in the world. They’re also extremely complex to operate and maintain, so we’re also giving Ukraine the parts and equipment necessary to effectively sustain these tanks on the battlefield."
The U.S. initially resisted Ukraine's demand for the highly sophisticated Abrams tanks, which require special fuel and maintenance and training.
So why the change of heart? reporters asked National Security Council spokesman John Kirby when he appeared at Wednesday's White House briefing:
"We have been — from the beginning of this war, now 11 months ago — been evolving the capabilities we’re providing with Ukraine with the conditions on the ground," Kirby said.
"What’s changed, Kristen, are the conditions on the ground and the kinds of fighting that the Russians are doing right now and the kinds of fighting, more importantly, that we believe the Ukrainians are going to be — need to be capable of in weeks and months ahead, well into 2023 — well into this year."
Kirby said the Russians are using a wintertime lull in the fighting to re-arm and re-group:
"But as the weather conditions improve, you can expect that the Russians are going to pick up the tempo. We have to be — we have to be ready for that. And I know the Ukrainians feel they have to be ready for that.
"So, it’s about helping Ukraine defend itself but also, as you heard the President say, helping Ukraine be able to go on the offense when the weather conditions and when the — when the operational conditions are permissive."
But Kirby admitted that the Abrams tanks "are not going to get there for many months." However, he added Germany's Leopard tanks "won't take quite as long to get there."
"And we’re not wasting the time," Kirby said:
"I mean, even as we procure these tanks, we’re going to be — the Pentagon will very soon start doing the training for Ukrainian tankers, Ukrainian troops that man tanks so that they can be ready to receive once those tanks are on the — on the battlefield.
Russia has warned that sending western tanks to Ukraine is escalatory. As CNBC reported, "The Russian Embassy in Berlin called the German government’s decision 'extremely dangerous' and said it 'takes the conflict to a new level of confrontation.'"
Kirby said the Biden administration is not "dismissive" of those warnings.
"That said, these tanks are meant to help Ukraine fight effectively on open terrain, to defend their sovereignty and their territory, and to win back territory that the Russians have taken from them.
"And as the President said, they don’t represent an offensive threat to Russia. Do they represent a threat to Russian soldiers? You bet they do. But not to — Russian soldiers that are in Ukraine, not — not to — not to Russia proper."
The Abrams tanks are just the latest in a long list of U.S./NATO military contributions to Ukraine since Russia invaded eleven months ago:
As President Biden said on Wednesday:
"Together with our Allies and partners, we’ve sent more than 3,000 armored vehicles, more than 8,000  artillery systems, more than 2 million rounds of artillery ammunition, and more than 50 advanced multi-launch rocket systems, anti-ship and air defense systems, all to help counter Ukraine’s [Ukraine counter] brutal aggression that is happening because of Russia," Biden said.
"And, look, today’s announcement builds on the hard work and commitment from countries around the world, led by the United States of America, to help Ukraine defend its sovereignty and its territorial integrity.
"That’s what this is about: helping Ukraine defend and protect Ukrainian land. It is not an offensive threat to Russia. We are — there is no offensive threat to Russia. If Russian troops returned to Russia, they’ll be there for — where they belong, and this war would be over today.
"That’s what we all want: an end to this war in just and lasting terms."