Is there such a thing as a "just war"?

Pope Leo’s showing he won’t by cowed by Donald Trump, who recently attacked him as weak and liberal after papal criticism of the Iran war. 

Leo hasn’t directly named the US President but during his visit to Africa, he’s referred to war, tyranny and to “spending billions of dollars on killing and devastation”.  

Vice President J.D. Vance, a recent convert to Catholicism, also decided to explain the theology of a “just war” to the pontiff. 

Some in the Trump administration even believe they’re waging a holy war. 

Where does such language mean and where can it lead? 

GUEST:

• Professor Darius Von Guttner is a Papal historian at the Australian Catholic University link