My name is Andrew Kramer. I'm a reporter for the New York Times. I'm standing on the highway where

Ukrainian troops are moving tanks and armored vehicles into Russia.

Every few minutes, we have tanks, trucks with soldiers,

rumbling past and in the direction of Russia.

From the New York Times, I'm Michael Bobaro.

This is the Daily.

Ukraine sliced through the border area, pushed through minefields and thinly manned

defences and has been pressing deeper into Russia.

When Ukraine's military crossed over into Russia two weeks ago. It appeared at first to be a largely symbolic

gesture. But in the time since, it's emerged as a defining moment in the two-year-old war.

This is the first major military incursion into Russia since World War II.

Today, Andrew Kramer on what's behind the audacious Ukrainian

operation and Anton Troyanovsky

on how Russia's response could reshape the conflict.

It's Wednesday, August 21st.

Andrew, I wonder if you can take us back to the moment when you discovered that this pretty unimaginable thing

had occurred, Ukrainian troops entering

Russian territory and turning the basic equation of this war upside down.

Well the entire operation was shrouded in secrecy.

So the first reports were actually from Russian social media posts and everything was a little bit vague.

We were seeing reports of fighting along the border, but nothing indicating the scale of what was

to come.

...