The question has to be taken apart into two, because the usual answer runs them together. Did Hegel ascribe an ethical significance to war? Yes. Did he declare war to be good? No – and at the same time he drew limits around war which today’s wars fail.
What Hegel claims
Since there is no judge above sovereign states – a league of nations would for him be a contract and not a state – war remains the last form of decision. Beyond that, in the note to § 324, he ascribes to it an ethical function: in war what is otherwise merely edifying talk becomes serious, namely the transience of possessions and life. For this he quotes an image from his own Jena essay: war preserves „the ethical health of nations in their indifference to the permanence of finite determinacies, just as the movement of the winds preserves the sea from the putrefaction into which a lasting calm would plunge it“.
That is the sentence at which the indignation catches fire, and it should not be talked down. But two things stand immediately beside it. First, Hegel says war is „not to be regarded as an absolute evil“ – not: that it is a good. Second, he himself adds that this is „merely a philosophical Idea“, and that „actual wars still require a different justification“.
The limit that nobody quotes
Immediately afterwards, in § 338, Hegel draws the boundary beyond which, for him, there is no war at all any more:
In the fact that states mutually recognize one another as such, there remains, even in war – that condition of rightlessness, violence, and contingency – a bond … It thus contains the determination, in accordance with international law, that the possibility of peace be preserved within it – so that, for example, envoys are respected – and, in general, that it not be waged against internal institutions and peaceful family and private life, nor against private persons.
Groundlines, § 338
In the lectures he becomes concrete. According to Griesheim’s transcript, whatever carries the common life remains untouched – „the administration of justice, churches, poor-houses, hospitals, all this is left to go its way, and likewise private life and the trades“; in the disarmed enemy „the human being is always recognised“. And in the course of 1822/23 stands the sentence that settles the matter: „A war of extermination can be waged only by fanaticism.“
With that a standard is set. A war that takes the civilian population, the hospitals and the supply of necessities as its target is by this standard not a war in Hegel’s sense, but what he attributes to fanaticism. Whoever invokes Hegel for such a war invokes a text that excludes it.
And perpetual peace?
Hegel rejects Kant’s proposal, but not because peace is indifferent to him. His objection in the note to § 333 is a fault of construction: a league of states presupposes „an agreement between states which – resting on moral, religious, or other grounds and considerations … – would remain afflicted with contingency“. In the Heidelberg course of 1817/18 he expressly concedes that the thought is „a well-meaning one … which is also morally good“ – and rejects it nonetheless.
What actually limits war is, in Hegel, something other than morality and something other than contract. It is the customs of nations (§ 339). Why there is nothing stronger he says in the course of 1822/23 in a single sentence: „There is no law above it, for a law requires a power that actualises it.“ This limit is therefore not enforceable – only losable.
Sources. § 324, § 333, § 338, § 339 · transcripts Wannenmann 1817/18, Hotho 1822/23, Griesheim 1824/25 (Gesammelte Werke 26,1–26,3) · Walter Kaufmann, „The Hegel Myth and Its Method“, 1959 · Jon Stewart (ed.), The Hegel Myths and Legends, 1996, there „The Myth that Hegel Glorified War“. – See also in the glossary: War, External Sovereignty.