Actually, under Putin's tutelage. He is the one threatening nukes because his conventional forces are incompetent and his "Special Military Action" has become a personal disaster.
Drumpf would have just let Putin roll over Ukraine.
It's weird then that Trump sent so many arms to Ukraine, and Putin didn't pull his invasion until Trump left. That doesn't really fit with your narrative. Under Biden's tutelage the world is much less secure. It's an inconvenient fact for many.
Remember when it was suppose to be Trump that crashed the economy and started WWIII? Turns out, it's Biden.