Well Trump has probably reduced the chances of a war involving...

Well Trump has probably reduced the chances of a war involving Iran by sabotaging Obama's nuclear deal with Iran. (By doing this he has motivated Iran to get a powerful nuclear arsenal as soon as possible thereby disadvantaging the US.)

Trump's order to murder Qasem Soleimani, the second most powerful person in Iran, based on phoney and extremely flimsy justifications, was another major blunder just to top things off.

Also during his first presidency he proved his inability to stand up to the warmongering US foreign policy elite when he did an abrupt U-turn on US relations with Russia.

Hopefully he has learnt something but at his age is he capable of changing his whole personality and replacing his pattern of irrational impulsive decisions with common sense. I don't think so.