The difficulty Trump has with the Pope, is that he (the pope) doesn't have an army (Swiss Guards excepted) much in the way of weapons and the territory of Vatican City is pretty small. tarriffs will not affect them, nor will oiland gas blockades. it doesn't have a navy either.
All the pope has to do is to do his job of leading the catholic church and speaking on morality, and just let Trump and his minions ramp up the personal abuse and ludicrous 'holy' pictures of Trump. I expect the next one will present him as Pope.
I note that the Pope, an American citizen, has decided not to go back to the US while Trump remains President. It is good to know that one country in the world has a head of state who is in his right mind and intelligent.