John Yoo recommends some summer reading:
The Richard Sharpe adventures, by Bernard Cornwell: Sometimes described as Patrick O’Brian novels, except on land, Cornwell’s 24 books describe the rise of Richard Sharpe: He starts as a private in Britain’s colonial army in India and becomes a lieutenant colonel by Waterloo. The focus of the books is on Wellington’s famous Peninsular Campaign, in which an outnumbered band of British troops, aided by vicious guerrillas (the first use of the word), pushed Napoleon’s armies out of Spain in hard, mountainous fighting.
A History of the English-Speaking Peoples, by Winston Churchill: Leaders on both sides of the pond are doing their very best to ruin the “special relationship”; this classic history explains why the ties that bind will survive any temporary failings in our leaders. Churchill writes history the way it was meant to be written, with flair, insight, and a focus on the great events and leaders of the day. I started reading Churchill while writing Crisis and Command — I came away thinking that, of all of the great prime ministers who have led Great Britain, only Churchill stands with Washington, Lincoln, and FDR among the greats.
The Personal Memoirs of Ulysses S. Grant and The Memoirs of General W. T. Sherman: In a day when civilian-military relations are at a low point, and in the midst of a tough war with rising casualties, it is important to remember how past generals in even worse wars handled both politicians and the enemy. Were it not for these men, Lincoln could not have saved the Union, and here we read how they did it, with an unsparing attention to casualties and setbacks as well as victories. Both books introduced modern American writing — they are sparse and free of the overwrought, ornamental writing typical of the 19th century. They are more the Gettysburg Address, and less an Obama speech on health care.
— John Yoo is a law professor at the University of California, Berkeley.
There are more suggestions, from many different authors, here and here.