It's an interesting scenario, especially for a story written before Parnell's electoral triumph of 1885. The context for the story is one of general European disintegration, as indeed was the case when push eventually did come to shove forty years after writing and thirty years after the story is set:
The year 1892 opened upon a gloomy prospect,—a period of impending strife and conflict in Europe. Eveiy-where discontent was manifest, and people grew more and more restless under the government of kings and princes. Nihilism, Socialism, and Democracy honeycombed and permeated every civilized community. The Russian government, as a last resort to escape destruction, had granted autonomy to long-suffering Poland ; the Turks had retired to the Asiatic side of the Bosphorus, whence they came ; and the Greeks, whose territory was now expanded to its ancient domain, occupied Constantinople as their original capital, Byzantium. Bosnia, Herzegovina, and Albania had been consolidated with Dalmatia as a Christian republic, called the Dalmatian League. Norway, separated from Sweden, had become a republic. The people of British North America had asked and had received autonomy, and were now the Republic of Canada. India, taking fire from the example of Christian lands, became restive, and consequently England had sent large bodies of troops thither ; but Ireland still occupied her old position, not as, according to the Act of Union, a component, sovereign part of the Empire, but as a vassal dependency.
The outbreak of a European conflict - Germany, allied with Austria, invades the Netherlands and Belgium - creates Ireland's opportunity; the Irish army, trained in America and with German support, lands near Ballina and fights a decisive battle with the British at the Moy River (I had slightly hoped that the title might refer to Moy in County Tyrone, but it was not to be). There is another battle at Grangegorman in Dublin, in which the Irish/German army unleashes the awesome destructive power of a super bomb, causing the surrender of the remnants of the British garrison, after which the victorious Irish army is welcomed with public celebration into every major city, including Belfast. King Edward's government must therefore sue for peace, and the newly independent Irish state becomes an earthly paradise.
I found it very interesting that the dispositions of the various Irish/German and British troops are given in considerable detail - it's as if the writer had been working out the scenarios with tabletop miniatures on maps of the territory, and I must say that in places it descends into a game report. What the writer misses, of course, is that when the war for Irish independence actually came it was irregular forces on both sides that shaped the outcome, including the police and auxiliary police. If you're writing in 1882 and reading about the Franco-Prussian War and the American Civil War, it's an understandable mistake to make - though the Balkan wars of 1877-79 clearly weren't scrutinised very closely except as news items (as is apparent from the opening paragraph above). One of Shaw's targets in Arms and the Man, written only a few years later and set in 1885, is the armchair war enthusiast who thinks it's all about glorious cavalry charges.
Another point that struck me was the political geography of Dublin, particularly as it relates to the 1916 Rising. Both military plans, from this book and real life, were fairly crazy. The Battle of the Moy has a victorious insurgent army coming in from the northwest and overwhelming the Brits after the Grangegorman kerfuffle. Pearse and Connolly seized the General Post Office, but failed to assert control of either Dublin Castle or indeed the actual phone exchange. But the wider point is that while we now think of the government quarter of Dublin as being in the block centred on Leinster House, in both 1882 and 1916 it was really Dublin Castle with an extension down to the Four Courts. I don't think there were any government buildings on Merrion Square until the Department of Agriculture arrived there in 1899. (The Battle of Moy is inconsistent as to whether the Irish Parliament returns to College Green before or after independence.)
Anyway, a short future history book of the past, well worth looking at if you are familiar with Irish geography and history, probably not otherwise. I wonder who wrote it?