What are the realistic alternatives in the Russia-Ukraine conflict?

According to the speaker, there are two realistic alternatives in the Russia-Ukraine conflict. The first option is a long, protracted Vietnam-style war continuing in the region, which suggests an ongoing conflict with significant casualties and resources spent without a clear resolution. The second alternative is a zero-sum game leading to World War III in an effort to fully defeat Russia, implying a dramatic escalation of the conflict to a global scale. The speaker considers this assessment to be the most realistic starting point for discussions about the situation.