The US Ambassador to NATO told Euronews only Putin can stop this war.
With the world's focus on Ukraine and what Russia will do next, NATO's headquarters in Brussels has been on high alert.
The White House's eyes and ears on the ground at the military alliance's base belong to Julianne Smith, the U.S. ambassador to NATO, who spoke to Euronews exclusively about the ongoing conflict between Kyiv and Moscow.
Was NATO prepared for a Russian invasion?
"The alliance was prepared actually for this. We basically, for several months now here at NATO's HQ, we've been pursuing a kind of a dual-track strategy. So, on the one hand, the allies were very focused on diplomacy and de-escalation - we held a NATO-Russia Council in early January where we were able to sit down face to face with the Russians.
"But simultaneously, what was happening behind the scenes was that NATO's allies were also preparing for all contingencies. They were looking at ways they might need in the future to reinforce NATO's eastern flank. And they were imagining the steps that they might have to take should Russia decide to further invade Ukraine.
"So when that actually came to pass, I think the NATO allies felt like at that moment they were ready to take the necessary steps to protect NATO's territory. And what we've seen really in the last couple of days is a remarkable series of events as it relates to NATO's and NATO's allies' actions."
Was it a mistake to trust Putin in diplomatic talks?
"Obviously, you wanted to have a moment to ensure that you could make the case to the Russians that de-escalation was the preferred and the best course of action. Sadly, they opted for another route. But we wanted to exhaust all possible options on the diplomatic front, and you can see that we did that bilaterally.
"The U.S. engaged the Russians in Geneva and elsewhere. We had NATO's engaging with the NATO-Russia Council, and the OSCE was engaging as well. So we all made a good faith effort at diplomacy, and again, unfortunately, they opted for another course of action.
Does Ukraine stand any chance of winning this war?
"It's hard to make any predictions at this point. I think what we would say is we're in awe of the resilience and the courage that we're seeing displayed by everyday Ukrainians, by the government, by the armed forces. It's really been remarkable to watch. It's also been reassuring in my mind to see all NATO's allies, in this moment, providing assistance to Ukrainians that takes different forms, depending on the NATO's ally and question.
"But NATO and the EU together are rising to this challenge and providing support to stop the war, to stop Vladimir Putin. I don't know what will ultimately stop the war. We hope Vladimir Putin will stop the war. It is on him. The only way out of this is for Moscow to stop invading. Stop these crushing attacks on cities across Ukraine. We want Russian forces to leave. We want to see a cease-fire. And all of us continue to drive that message home to Moscow.
What about Putin's nuclear threats?
"Obviously, what we heard coming out of Moscow on their intent to increase the readiness or the alert level of their nuclear forces was incredibly provocative, dangerous, troubling. We're worried that this can increase the chance of miscalculation.
"NATO, however, and the United States, neither one wants to have any sort of conflict with Russia. And as you've heard, colleagues of mine back in Washington state, we are not making any adjustments to our alert levels at this point."
Is NATO membership for Ukraine still an option?
"Ukraine is a partner to this alliance and has a very close relationship with the alliance. We've been working with Ukraine over many years now on ensuring that they can take the necessary steps for membership. We've been crystal clear in our messaging both to the Russians in early January and at the summit communique last summer that the door to narrow enlargement remains open and Russia does not have a veto over that process.
"So we believe here at NATO that the enlargement decision rests squarely with the aspirant country, in this case, Ukraine and the 30 members of the alliance. It has nothing to do with Russia or Moscow's views."