Feb. 24 marked the one-year anniversary of Vladimir Putin's launch of an unprovoked and, U.S. leaders say, indefensible invasion of his democratic neighbor Ukraine. But what some, including Putin, likely thought would be a quick march to Russian victory, has become a protracted and costly war, but one that Ukrainians believe they will ultimately win.

The United States has committed about $80 billion in aid to Ukraine in the last year, about $50 billion of that has been military aid. That and military training prior to the invasion, many agree, have made a difference

"Yeah, I believe that because I witnessed that," said Andriana Zmysla, a 36-year-old Ukrainian now living in London.

In the years leading up to the invasion, Zmysla worked as an interpreter at the Yavoriv military base in Western Ukraine. The base is home to the Joint Multinational Training Group-Ukraine (JMTGU) where western allies, including the U.S. -- and in 2017, the Oklahoma National Guard -- provided training to Ukrainian soldiers.

"And I think even now they are using these skills and this invaluable training," Zmysla said in a zoom interview Friday morning.

Russian missiles destroyed the training complex three weeks into the invasion, killing several of Zmysla's colleagues. She said she lost another two more recently.

"They were interpreters with me," she said, "and they're 30 years old, very fit guys, and they volunteered to go to the front line and, unfortunately, they both were killed in action."

It's estimated 13,000 Ukrainian soldiers have been killed in the invasion thus far, while Russian deaths are believed to be about triple that, close to 45,000. Civilian deaths are put at about 8,000.

Zmysla translated for news crews covering the invasion in its first weeks but decided to move to the United Kingdom in April.

She said she gets back to Ukraine every two months to see family and friends and remains engaged abroad.

"Even today, after this interview," Zmysla said, "I’m going to a protest near the Russian Embassy."

When she's not speaking out against Russia, she said she's learning a new trade -- information technology.

"And then, when the war is over," she said, "maybe [I'll] come back and help rebuild Ukraine...help to create a new Ukraine."

Zmysla is not optimistic that will be soon. But she does believe, with superior military leadership and an absolute refusal to give up, Ukraine will defeat Russia. She said they must.

"If we don’t win this war -- if our generation doesn’t win this war," Zmysla stated, "in 10, 20 or 30 years, our children will have the same problems."