Max Boot is a leading military historian and foreign-policy analyst. The Jeane J. Kirkpatrick Senior Fellow in National Security Studies at the Council on Foreign Relations in New York, he is also a contributing editor to the Weekly Standard and the Los Angeles Times.

It isn’t getting much press here in the States, but in Britain and Ireland the visit of Queen Elizabeth II to the Republic is very big news indeed. And justifiably so: it is the first visit by a British monarch to southern Ireland since 1911, when it was still a British colony. Within ten years Ireland had become independent, the first colony to do so since the 13 American colonies won their freedom in 1782. The Irish victory in their War of Independence shook imperial self-confidence and presaged further revolts that within a few decades would lead to the sun’s setting on an empire that once spanned the globe.

The man who more than any other was responsible for this outcome was Michael Collins, the IRA’s director of intelligence and its de-facto commanding general. Terrorists have gotten a bad name, and rightly so, but if ever there was a good terrorist it was the fun-loving, hard-living “Mick.” Unlike so many of those who have practiced terrorism in more recent years, Collins avoided indiscriminate attacks on civilians.  He vetoed schemes such as the proposed truck-bombing of the House of Commons. Instead he directed most of his energies to targeting British agents and their Irish collaborators.

Like any other civil war—including the American Revolution—the Irish War of Independence had its share of atrocities. IRA operatives killed civilians accused of being informants, and British officers sometimes tortured IRA prisoners to extract information. But on the whole, it was far more humanely conducted on both sides than most civil wars before or since....