"I am hoping that Vladimir Putin understands that he is — short of a full-blown nuclear war, he’s not in a very good position to dominate the world."

Did Biden inadvertently — obliquely — advise Putin to use nuclear weapons? 

From the transcript: 

I’m very concerned that this could end up being — look, the only war that’s worse than one that’s intended is one that’s unintended. And what I’m concerned about is this could get out of hand — very easily get out of hand because of what you said: the borders of the — of Ukraine and what Russia may or may not do. I am hoping that Vladimir Putin understands that he is — short of a full-blown nuclear war, he’s not in a very good position to dominate the world. And so, I don’t think he thinks that, but it is a concern. And that’s why we have to be very careful about how we move forward and make it clear to him that there are prices to pay that could, in fact, cost his country an awful lot. But I — of course, you have to be concerned when you have, you know, a nuclear power invade — this has — if he invades — it hasn’t happened since World War Two. This will be the most consequential thing that’s happened in the world, in terms of war and peace, since World War Two.

What hasn't happened since World War II? That a nuclear power has invaded? (Is that true, and, if it's true, how did you have to interpret "invade" to get it to be true?) Or was he saying the thing that hasn't happened since WWII is the use of nuclear weapons? 

Notice that he said "when you have... a nuclear power invade" and then changed it to "if he invades."

"The only war that’s worse than one that’s intended is one that’s unintended" — what is the unintended war? Nuclear war?! He's "concerned" that "this could... very easily get out of hand." Is he not talking about nuclear war? This seems less careful about nuclear war than what we've seen from past Presidents.  It could "very easily get out of hand because... the borders of the — of Ukraine." He stops, but I believe the point is that right next to Ukraine, there are NATO nations:

And, you know, we’re going to fortify our NATO Allies, I told him, on the eastern flank....

The point seems to be go ahead and take Ukraine, but don't go any further:

The cost of going into Ukraine, in terms of physical loss of life, for the Russians, they’ll — they’ll be able to prevail over time, but it’s going to be heavy, it’s going to be real, and it’s going to be consequential.

He directly tells Putin he will win Ukraine and is concentrating on warning Putin against going any further. Biden's ambiguous mutterings about nuclear war seem to relate to invasions beyond Ukraine.