Trump actually said this during his announcement speech:
“I’ve gone decades, decades without a war, the first president to do it for a long period.”
Trump's speech was pathetic, so obviously a desperate cry for attention and recognition. I wonder how many of the right wing media outlets that constantly question Biden's mental competence even mentioned this gaffe. Or maybe they attributed it to his greatness, that he can retroactively produce peace for decades despite only being president for four years, or even six if you consider that he, you know, really won the 2020 election by a landslide but it was stolen from him. Like his other power of declassifying hundreds of documents by thought alone.