Hugo Grotius discusses the just causes of going to war, especially the idea that the capacity to wage war must be matched by the intent to do so (1625)
Found in The Rights of War and Peace (2005 ed.) vol. 2 (Book II)
Hugo Grotius attempted to codify the historical, moral, and legal grounds for justly waging war against an enemy. Here are his thoughts on waging war against a perceived threat:
First therefore, the Dread (as we before observed) of our Neighbour’s encreasing Strength, is not a warrantable Ground for making War upon him. To justify taking up Arms in our own Defence, there ought to be a Necessity for so doing, which there is not, unless we are sure, with a moral Certainty, that he has not only Forces sufficient, but a full Intention to injure us.
We first used a quotation from Grotius' The Rights of War and Peace in May 2004 and the edition we used was from 1901. Since then the marvelous three volume edition published by Liberty Fund and edited by Richard Tuck has appeared (2005) which supercedes all earlier editions and translations. In this quotation Grotius explores an important contemporary topic, when is it just to go to war?