Dear old Tommy! Thanks for that - let's have a look at these oft-quoted rules from the dark ages of superstition and irrationality. I love this bloke!
The war must be started and controlled by the authority of state or ruler.
There must be a just cause.
The war must be for good, or against evil. Law and order must always be restored.
This is why Hitler was a catholic - he could 100%, cast-iron guarantee he was fighting a just war.
He was unquestionably head of state when started WWII. Tick.
He had a multitude of just causes! Liebensraum, Wiemar, spreading Communism/Bolshevism, the British, the French.... The Maginot Line was built before the Siegfried. Tick, tick, tick!
And a final tick on point 3. The war for good against evil - Germany had virtually no dominions against the 3/4 of the globe owned and run by the Frech and the Imerial Brits. Add into that the restrictions placed on Germany by its previous conquerors and the several hundred years of hatred and attempted invasion by the French, and there can have been few wars as just.
Hitler was a big fan of law & order, too.
Even looking at the extra couple of needs added in by the RCC, as contained in the article, Hitler must have been comfortable with starting a war.
The war must be a last resort.
No doubt about that one.
The war must be fought proportionally.
(This ambiguous statement is taken to mean: do not use more force than necessary or kill more civilians than necessary.)
Right from the start, Adolf was organised along those lines; he didn't attack civilians to any great degree - other than Jews, but since they did kill Jesus, it's probably ok. The great sweep through the low countries spared many civilians, Paris was not destroyed by bombers and I must note that Germany's immense air forces were used to bomb military targets until Churchill decided to bomb Berlin.