Benedict Arnold has been called many things over the last two centuries, but here's a rap that's never been pinned on him: terrorist.

For all the hatred he has earned for reducing New London to ashes in 1781, he has at least gotten the benefit of the doubt that his actions should be framed in a wartime context.

A new book on Arnold's dark career argues that terror more than treason should be his legacy. "Homegrown Terror: Benedict Arnold and the Burning of New London" is a fresh take on a familiar story and may be the first book on Arnold to give his attack on New London and Groton, little known outside these parts, its due.

Author Eric D. Lehman, a professor at the University of Bridgeport, makes several provocative assertions, all in a preface, before the book settles into a narrative of Arnold's life from his childhood in Norwich to his ignominious last days in England.

While calling Arnold a terrorist is an attention-getter, Lehman makes his case with nuance, arguing that the terms we use to define good and evil change over time. "Terrorist" resonates with 21st-century Americans in a way "traitor" no longer does. Few people called Timothy McVeigh a traitor even though he met the definition.

Lehman also offers a reaction against a recent trend in scholarship. It has become fashionable to take a balanced view of Arnold by weighing his early military accomplishments for the American Revolution against his treason to somehow soften the severity of the crime.

While Arnold's battlefield feats are undeniable, Lehman argues he is fully worthy of the moral revulsion history had accorded him until recent years. How he does this is what makes "Homegrown Terror" feel different from other accounts of Arnold's career.

Many books put the focus on the endlessly fascinating question of what motivated him to betray his country. Lehman, rather than examine the cause, emphasizes the effects of his treason.

The betrayal was a psychological blow to the new nation, which had come to think of him as a hero. His commander, George Washington, who had been a supportive friend, wanted him captured alive so he could be hanged.

But perhaps the biggest shock was felt by the community of Connecticut revolutionaries of which Arnold had lately been a part. One of their own had turned against them, and the devastating news of his attempt to turn over West Point to the British was only the beginning.

Lehman spends time examining this community. It included Nathaniel Shaw, a maritime trader in New London who coordinated naval activities; Samuel Huntington of Norwich, a signer of the Declaration of Independence who rose to become president of the Continental Congress; and Silas Deane, whose diplomacy brought French aid to the cause.

There was also a young schoolteacher named Nathan Hale and his friend Benjamin Tallmadge, both of whom would become spies; Israel Putnam, a general who fought at Bunker Hill; and William Ledyard, who labored to defend New London Harbor, building Fort Griswold with his own hands.

Presiding was Jonathan Trumbull, the only colonial governor to side with the revolutionaries. Running Connecticut's war effort from his tiny store on the Lebanon Green, he expertly undertook the unglamorous task of supplying the army and came to Washington's rescue more than once.

And then there was Benedict Arnold, who time and again distinguished himself on the battlefield until he fell wounded at Saratoga. Sidelined, he became military ruler of Philadelphia, where, abetted by his loyalist wife and nursing old grudges, he switched sides.

This period, leading up to Arnold's treason at West Point, is well-worn territory and usually treated as the culmination of his life, with what came afterward a mere footnote.

Lehman goes at it differently, depicting West Point as the turning point it was but not as Arnold's ultimate descent into villainy. At that stage, he had become a political traitor, but he soon one-upped himself by taking up arms against his countrymen.

He talked his British superiors into command of a raiding expedition to Virginia. The lengthy campaign put in motion a chain of events that brought Lord Cornwallis' army to Virginia and set the stage for the war's end.

By that point, Arnold had returned to British-held New York, where he was given a new assignment. He was sent to attack New London, a hive of privateering vessels that had long annoyed the British. With the French fleet speeding to Virginia to trap Cornwallis, the rationale for attacking New London has never been clear.

But for Arnold, the mission would blacken his name even further, which hardly seemed possible. First he had betrayed his country, then fought against it. Now he would turn British guns and torches on his own neighbors. It was this, Lehman contends, that cemented his infamy.

The book offers two startling facts not generally known. New London suffered the most damage of any American city in the war. Groton Heights had the highest percentage of casualties of any battle.

In view of this, it's hard to understand why stories have persisted that Arnold did not intend for so much of New London to be burned, or for his troops to commit a massacre in Groton. Lehman dismisses such notions as not being in Arnold's interest. He was trying to impress his superiors with cold-blooded effectiveness, which left little room for mercy, even toward civilians he knew personally.

"If the 'rules' of war are broken, if civilian populations are bombed or burned, then 'terror' seems the appropriate reaction, and perhaps an appropriate word," Lehman writes.

Just before the war's end at Yorktown, the Marquis de Lafayette issued a three-word order to Connecticut troops under his command. It can be taken today as a plea to historians to right a longstanding wrong, one that "Homegrown Terror" has done its part to address.

He told them, "Remember New London."

"Homegrown Terror: Benedict Arnold and the Burning of New London" by Eric D. Lehman; Wesleyan University Press; 261 pages; $30

j.ruddy@theday.com

Twitter: @jruddy64