This is Trump. He's not going to war with Russia but if he gets out of the wrong side of his bed and reads the wrong social media post he might have to get talked out of nuking Portland
... but with China instead. The trouble with this guy is, you can't be sure if what he spouts from his mouth is him being actually serious, him just parroting whatever the last person to talk to him said (seems to be a common trope regarding anything Ukraine) or if he's just out of his mind and gone off script, off rails. And on top of that you got stuff like the sinking of the "Venezuelan drug boats" that would be seen as and dealt with as a declaration of war if the aggressor weren't the USA.
All it takes for stuff to go Seriously Damn Wrong is one person on the other side taking his verbal diarrhoea seriously and literally and acting accordingly.