Trump nearly got the US into a full-blown shooting war with Iran in January 2020, when he ordered the top general in Iran killed. The only reason it didn't start is that the Iranians took favorable international opinion and promptly shot down a neutral commercial airliner leaving Tehran.
It shows how crazy 2020 turned out to be that everyone has completely forgotten about this.
The reason the likelihood of WW3 starting in the Taiwan Strait or Korean DMZ is much higher because the US is tied much tighter by treaty to Japan, South Korea, and Taiwan than they are to the Ukraine. I think business like this is why NATO has been very slow to consider their admission into the bloc at any level, unlike the Baltic states, which were promptly admitted at independence.