If you’re adapting or appropriating Thomas Aquinas’s thoughts about just war, it could be difficult to argue that Henry V’s war with France meets Aquinas’s criteria.

The one component that seems to align with Aquinas’s thoughts is that of a just authority. For Aquinas, a war is invalid if the government waging that war isn’t credible or legitimate. It seems like Henry V is valid and licit. He is the accepted king of England. It’s his throne, and it’s within his rights to declare war.

However, with that being said, you could adopt the perspective that Henry V shouldn’t be viewed as a legitimate authority. It’s not like Henry V became king because of a free election. The people of England didn’t choose Henry V to be their king. If you espouse a democratic perspective, you might conclude that Henry V is not a legitimate authority.

As for a just cause and a just intention, if you adopted Henry V’s perspective, perhaps you could argue that the cause and intention were just. The war netted Henry V an upset victory, a wife, and something like a hero’s welcome.

Yet if you take up the perspective of the common soldier, it might be hard to argue that this war was necessary. As Henry V’s undercover conversations with the rank-and-file soldiers indicate, the war was almost all risk and no reward for them.